--- OA_place: publisher _id: '6363' abstract: - lang: eng text: "Distinguishing between similar experiences is achieved by the brain \ in a process called pattern separation. In the hippocampus, pattern \ separation reduces the interference of memories and increases the storage capacity by decorrelating similar inputs patterns of neuronal activity into \ non-overlapping output firing patterns. Winners-take-all (WTA) mechanism \ is a theoretical model for pattern separation in which a \"winner\" \ cell suppresses the activity of the neighboring neurons through feedback inhibition. However, if the network properties of the dentate gyrus support WTA as a biologically conceivable model remains unknown. Here, we showed that the connectivity rules of PV+interneurons and their synaptic properties are optimizedfor efficient pattern separation. We found using multiple whole-cell in vitrorecordings that PV+interneurons mainly connect to granule cells (GC) through lateral inhibition, a form of feedback inhibition in which a GC inhibits other GCs but not \ itself through the activation of PV+interneurons. Thus, lateral inhibition between GC–PV+interneurons was ~10 times more abundant than recurrent connections. Furthermore, the GC–PV+interneuron connectivity was more spatially confined \ but less abundant than PV+interneurons–GC connectivity, leading to an \ asymmetrical distribution of excitatory and inhibitory connectivity. Our network model of the dentate gyrus with incorporated real connectivity rules efficiently decorrelates neuronal activity patterns using WTA as the primary mechanism. \ This process relied on lateral inhibition, fast-signaling properties of \ PV+interneurons and the asymmetrical distribution of excitatory and inhibitory connectivity. Finally, we found that silencing the activity of PV+interneurons in vivoleads to acute deficits in discrimination between similar environments, suggesting that PV+interneuron networks are necessary for behavioral relevant computations. Our results demonstrate that PV+interneurons possess unique connectivity and fast signaling properties that confer to the dentate \ gyrus network properties that allow the emergence of pattern separation. Thus, our results contribute to the knowledge of how specific forms of network organization underlie sophisticated types of information processing. \r\n" alternative_title: - ISTA Thesis article_processing_charge: No author: - first_name: 'Claudia ' full_name: 'Espinoza Martinez, Claudia ' id: 31FFEE2E-F248-11E8-B48F-1D18A9856A87 last_name: Espinoza Martinez orcid: 0000-0003-4710-2082 citation: ama: Espinoza Martinez C. Parvalbumin+ interneurons enable efficient pattern separation in hippocampal microcircuits. 2019. doi:10.15479/AT:ISTA:6363 apa: Espinoza Martinez, C. (2019). Parvalbumin+ interneurons enable efficient pattern separation in hippocampal microcircuits. Institute of Science and Technology Austria. https://doi.org/10.15479/AT:ISTA:6363 chicago: Espinoza Martinez, Claudia . “Parvalbumin+ Interneurons Enable Efficient Pattern Separation in Hippocampal Microcircuits.” Institute of Science and Technology Austria, 2019. https://doi.org/10.15479/AT:ISTA:6363. ieee: C. Espinoza Martinez, “Parvalbumin+ interneurons enable efficient pattern separation in hippocampal microcircuits,” Institute of Science and Technology Austria, 2019. ista: Espinoza Martinez C. 2019. Parvalbumin+ interneurons enable efficient pattern separation in hippocampal microcircuits. Institute of Science and Technology Austria. mla: Espinoza Martinez, Claudia. Parvalbumin+ Interneurons Enable Efficient Pattern Separation in Hippocampal Microcircuits. Institute of Science and Technology Austria, 2019, doi:10.15479/AT:ISTA:6363. short: C. Espinoza Martinez, Parvalbumin+ Interneurons Enable Efficient Pattern Separation in Hippocampal Microcircuits, Institute of Science and Technology Austria, 2019. corr_author: '1' date_created: 2019-04-30T11:56:10Z date_published: 2019-04-30T00:00:00Z date_updated: 2026-04-08T13:57:19Z day: '30' ddc: - '570' degree_awarded: PhD department: - _id: PeJo doi: 10.15479/AT:ISTA:6363 file: - access_level: open_access checksum: 77c6c05cfe8b58c8abcf1b854375d084 content_type: application/pdf creator: cespinoza date_created: 2019-05-07T16:00:39Z date_updated: 2021-02-11T11:17:15Z embargo: 2020-05-09 file_id: '6389' file_name: Espinozathesis_all2.pdf file_size: 13966891 relation: main_file - access_level: closed checksum: f6aa819f127691a2b0fc21c76eb09746 content_type: application/vnd.openxmlformats-officedocument.wordprocessingml.document creator: cespinoza date_created: 2019-05-07T16:00:48Z date_updated: 2020-07-14T12:47:28Z embargo_to: open_access file_id: '6390' file_name: Espinoza_Thesis.docx file_size: 11159900 relation: source_file file_date_updated: 2021-02-11T11:17:15Z has_accepted_license: '1' language: - iso: eng month: '04' oa: 1 oa_version: Published Version page: '140' publication_identifier: isbn: - 978-3-99078-000-8 issn: - 2663-337X publication_status: published publisher: Institute of Science and Technology Austria related_material: record: - id: '21' relation: part_of_dissertation status: public status: public supervisor: - first_name: Peter M full_name: Jonas, Peter M id: 353C1B58-F248-11E8-B48F-1D18A9856A87 last_name: Jonas orcid: 0000-0001-5001-4804 title: Parvalbumin+ interneurons enable efficient pattern separation in hippocampal microcircuits type: dissertation user_id: ba8df636-2132-11f1-aed0-ed93e2281fdd year: '2019' ... --- OA_place: publisher _id: '7132' abstract: - lang: eng text: "A major challenge in neuroscience research is to dissect the circuits that orchestrate behavior in health and disease. Proteins from a wide range of non-mammalian species, such as microbial opsins, have been successfully transplanted to specific neuronal targets to override their natural communication patterns. The goal of our work is to manipulate synaptic communication in a manner that closely incorporates the functional intricacies of synapses by preserving temporal encoding (i.e. the firing pattern of the presynaptic neuron) and connectivity (i.e. target specific synapses rather than specific neurons). Our strategy to achieve this goal builds on the use of non-mammalian transplants to create a synthetic synapse. The mode of modulation comes from pre-synaptic uptake of a synthetic neurotransmitter (SN) into synaptic vesicles by means of a genetically targeted transporter selective for the SN. Upon natural vesicular release, exposure of the SN to the synaptic cleft will modify the post-synaptic potential through an orthogonal ligand gated ion channel. To achieve this goal we have functionally characterized a mixed cationic methionine-gated ion channel from Arabidopsis thaliana, designed a method to functionally characterize a synthetic transporter in isolated synaptic vesicles without the need for transgenic animals, identified and extracted multiple prokaryotic uptake systems that are substrate specific for methionine (Met), and established a primary/cell line co-culture system that would allow future combinatorial testing of this orthogonal transmitter-transporter-channel trifecta.\r\nSynthetic synapses will provide a unique opportunity to manipulate synaptic communication while maintaining the electrophysiological integrity of the pre-synaptic cell. In this way, information may be preserved that was generated in upstream circuits and that could be essential for concerted function and information processing." alternative_title: - ISTA Thesis article_processing_charge: No author: - first_name: Catherine full_name: Mckenzie, Catherine id: 3EEDE19A-F248-11E8-B48F-1D18A9856A87 last_name: Mckenzie citation: ama: Mckenzie C. Design and characterization of methods and biological components to realize synthetic neurotransmission. 2019. doi:10.15479/at:ista:7132 apa: Mckenzie, C. (2019). Design and characterization of methods and biological components to realize synthetic neurotransmission. Institute of Science and Technology Austria. https://doi.org/10.15479/at:ista:7132 chicago: Mckenzie, Catherine. “Design and Characterization of Methods and Biological Components to Realize Synthetic Neurotransmission.” Institute of Science and Technology Austria, 2019. https://doi.org/10.15479/at:ista:7132. ieee: C. Mckenzie, “Design and characterization of methods and biological components to realize synthetic neurotransmission,” Institute of Science and Technology Austria, 2019. ista: Mckenzie C. 2019. Design and characterization of methods and biological components to realize synthetic neurotransmission. Institute of Science and Technology Austria. mla: Mckenzie, Catherine. Design and Characterization of Methods and Biological Components to Realize Synthetic Neurotransmission. Institute of Science and Technology Austria, 2019, doi:10.15479/at:ista:7132. short: C. Mckenzie, Design and Characterization of Methods and Biological Components to Realize Synthetic Neurotransmission, Institute of Science and Technology Austria, 2019. corr_author: '1' date_created: 2019-11-27T09:07:14Z date_published: 2019-06-27T00:00:00Z date_updated: 2026-05-14T22:31:07Z day: '27' ddc: - '571' - '573' degree_awarded: PhD department: - _id: HaJa doi: 10.15479/at:ista:7132 file: - access_level: closed checksum: 34d0fe0f6e0af97b5937205a3e350423 content_type: application/vnd.openxmlformats-officedocument.wordprocessingml.document creator: dernst date_created: 2019-11-27T09:06:10Z date_updated: 2020-07-14T12:47:50Z file_id: '7133' file_name: McKenzie PhD Thesis August 2018 - Corrected Final.docx file_size: 5054633 relation: source_file - access_level: open_access checksum: 140dfb5e3df7edca34f4b6fcc55d876f content_type: application/pdf creator: dernst date_created: 2019-11-27T09:06:10Z date_updated: 2020-07-14T12:47:50Z file_id: '7134' file_name: McKenzie PhD Thesis August 2018 - Corrected Final.pdf file_size: 3231837 relation: main_file file_date_updated: 2020-07-14T12:47:50Z has_accepted_license: '1' language: - iso: eng month: '06' oa: 1 oa_version: Published Version page: '95' publication_identifier: issn: - 2663-337X publication_status: published publisher: Institute of Science and Technology Austria related_material: record: - id: '6266' relation: old_edition status: public status: public supervisor: - first_name: Harald L full_name: Janovjak, Harald L id: 33BA6C30-F248-11E8-B48F-1D18A9856A87 last_name: Janovjak orcid: 0000-0002-8023-9315 title: Design and characterization of methods and biological components to realize synthetic neurotransmission type: dissertation user_id: ba8df636-2132-11f1-aed0-ed93e2281fdd year: '2019' ... --- _id: '6189' abstract: - lang: eng text: 'Suspended particles can alter the properties of fluids and in particular also affect the transition fromlaminar to turbulent flow. An earlier study [Mataset al.,Phys. Rev. Lett.90, 014501 (2003)] reported howthe subcritical (i.e., hysteretic) transition to turbulent puffs is affected by the addition of particles. Here weshow that in addition to this known transition, with increasing concentration a supercritical (i.e.,continuous) transition to a globally fluctuating state is found. At the same time the Newtonian-typetransition to puffs is delayed to larger Reynolds numbers. At even higher concentration only the globallyfluctuating state is found. The dynamics of particle laden flows are hence determined by two competinginstabilities that give rise to three flow regimes: Newtonian-type turbulence at low, a particle inducedglobally fluctuating state at high, and a coexistence state at intermediate concentrations.' article_number: '114502' article_processing_charge: No arxiv: 1 author: - first_name: Nishchal full_name: Agrawal, Nishchal id: 469E6004-F248-11E8-B48F-1D18A9856A87 last_name: Agrawal - first_name: George H full_name: Choueiri, George H id: 448BD5BC-F248-11E8-B48F-1D18A9856A87 last_name: Choueiri - first_name: Björn full_name: Hof, Björn id: 3A374330-F248-11E8-B48F-1D18A9856A87 last_name: Hof orcid: 0000-0003-2057-2754 citation: ama: Agrawal N, Choueiri GH, Hof B. Transition to turbulence in particle laden flows. Physical Review Letters. 2019;122(11). doi:10.1103/PhysRevLett.122.114502 apa: Agrawal, N., Choueiri, G. H., & Hof, B. (2019). Transition to turbulence in particle laden flows. Physical Review Letters. American Physical Society. https://doi.org/10.1103/PhysRevLett.122.114502 chicago: Agrawal, Nishchal, George H Choueiri, and Björn Hof. “Transition to Turbulence in Particle Laden Flows.” Physical Review Letters. American Physical Society, 2019. https://doi.org/10.1103/PhysRevLett.122.114502. ieee: N. Agrawal, G. H. Choueiri, and B. Hof, “Transition to turbulence in particle laden flows,” Physical Review Letters, vol. 122, no. 11. American Physical Society, 2019. ista: Agrawal N, Choueiri GH, Hof B. 2019. Transition to turbulence in particle laden flows. Physical Review Letters. 122(11), 114502. mla: Agrawal, Nishchal, et al. “Transition to Turbulence in Particle Laden Flows.” Physical Review Letters, vol. 122, no. 11, 114502, American Physical Society, 2019, doi:10.1103/PhysRevLett.122.114502. short: N. Agrawal, G.H. Choueiri, B. Hof, Physical Review Letters 122 (2019). date_created: 2019-03-31T21:59:12Z date_published: 2019-03-22T00:00:00Z date_updated: 2026-05-14T22:31:11Z day: '22' department: - _id: BjHo doi: 10.1103/PhysRevLett.122.114502 external_id: arxiv: - '1809.06358' isi: - '000461922000006' pmid: - '30951357' intvolume: ' 122' isi: 1 issue: '11' language: - iso: eng main_file_link: - open_access: '1' url: https://arxiv.org/abs/1809.06358 month: '03' oa: 1 oa_version: Preprint pmid: 1 publication: Physical Review Letters publication_identifier: eissn: - 1079-7114 issn: - 0031-9007 publication_status: published publisher: American Physical Society quality_controlled: '1' related_material: record: - id: '9728' relation: dissertation_contains status: public scopus_import: '1' status: public title: Transition to turbulence in particle laden flows type: journal_article user_id: ba8df636-2132-11f1-aed0-ed93e2281fdd volume: 122 year: '2019' ... --- _id: '6830' article_processing_charge: No article_type: letter_note author: - first_name: Ximena full_name: Contreras, Ximena id: 475990FE-F248-11E8-B48F-1D18A9856A87 last_name: Contreras - first_name: Simon full_name: Hippenmeyer, Simon id: 37B36620-F248-11E8-B48F-1D18A9856A87 last_name: Hippenmeyer orcid: 0000-0003-2279-1061 citation: ama: Contreras X, Hippenmeyer S. Memo1 tiles the radial glial cell grid. Neuron. 2019;103(5):750-752. doi:10.1016/j.neuron.2019.08.021 apa: Contreras, X., & Hippenmeyer, S. (2019). Memo1 tiles the radial glial cell grid. Neuron. Elsevier. https://doi.org/10.1016/j.neuron.2019.08.021 chicago: Contreras, Ximena, and Simon Hippenmeyer. “Memo1 Tiles the Radial Glial Cell Grid.” Neuron. Elsevier, 2019. https://doi.org/10.1016/j.neuron.2019.08.021. ieee: X. Contreras and S. Hippenmeyer, “Memo1 tiles the radial glial cell grid,” Neuron, vol. 103, no. 5. Elsevier, pp. 750–752, 2019. ista: Contreras X, Hippenmeyer S. 2019. Memo1 tiles the radial glial cell grid. Neuron. 103(5), 750–752. mla: Contreras, Ximena, and Simon Hippenmeyer. “Memo1 Tiles the Radial Glial Cell Grid.” Neuron, vol. 103, no. 5, Elsevier, 2019, pp. 750–52, doi:10.1016/j.neuron.2019.08.021. short: X. Contreras, S. Hippenmeyer, Neuron 103 (2019) 750–752. date_created: 2019-08-25T22:00:50Z date_published: 2019-09-04T00:00:00Z date_updated: 2026-05-14T22:31:13Z day: '04' department: - _id: SiHi doi: 10.1016/j.neuron.2019.08.021 external_id: isi: - '000484400200002' pmid: - '31487522' intvolume: ' 103' isi: 1 issue: '5' language: - iso: eng main_file_link: - open_access: '1' url: https://doi.org/10.1016/j.neuron.2019.08.021 month: '09' oa: 1 oa_version: Published Version page: 750-752 pmid: 1 publication: Neuron publication_identifier: eissn: - 1097-4199 issn: - 0896-6273 publication_status: published publisher: Elsevier quality_controlled: '1' related_material: record: - id: '7902' relation: part_of_dissertation status: public scopus_import: '1' status: public title: Memo1 tiles the radial glial cell grid type: journal_article user_id: ba8df636-2132-11f1-aed0-ed93e2281fdd volume: 103 year: '2019' ... --- _id: '6780' abstract: - lang: eng text: "In this work, we consider the almost-sure termination problem for probabilistic programs that asks whether a\r\ngiven probabilistic program terminates with probability 1. Scalable approaches for program analysis often\r\nrely on modularity as their theoretical basis. In non-probabilistic programs, the classical variant rule (V-rule)\r\nof Floyd-Hoare logic provides the foundation for modular analysis. Extension of this rule to almost-sure\r\ntermination of probabilistic programs is quite tricky, and a probabilistic variant was proposed in [16]. While the\r\nproposed probabilistic variant cautiously addresses the key issue of integrability, we show that the proposed\r\nmodular rule is still not sound for almost-sure termination of probabilistic programs.\r\nBesides establishing unsoundness of the previous rule, our contributions are as follows: First, we present a\r\nsound modular rule for almost-sure termination of probabilistic programs. Our approach is based on a novel\r\nnotion of descent supermartingales. Second, for algorithmic approaches, we consider descent supermartingales\r\nthat are linear and show that they can be synthesized in polynomial time. Finally, we present experimental\r\nresults on a variety of benchmarks and several natural examples that model various types of nested while\r\nloops in probabilistic programs and demonstrate that our approach is able to efficiently prove their almost-sure\r\ntermination property" article_number: '129' article_processing_charge: No arxiv: 1 author: - first_name: Mingzhang full_name: Huang, Mingzhang last_name: Huang - first_name: Hongfei full_name: Fu, Hongfei last_name: Fu - first_name: Krishnendu full_name: Chatterjee, Krishnendu id: 2E5DCA20-F248-11E8-B48F-1D18A9856A87 last_name: Chatterjee orcid: 0000-0002-4561-241X - first_name: Amir Kafshdar full_name: Goharshady, Amir Kafshdar id: 391365CE-F248-11E8-B48F-1D18A9856A87 last_name: Goharshady orcid: 0000-0003-1702-6584 citation: ama: 'Huang M, Fu H, Chatterjee K, Goharshady AK. Modular verification for almost-sure termination of probabilistic programs. In: Proceedings of the 34th ACM International Conference on Object-Oriented Programming, Systems, Languages, and Applications . Vol 3. ACM; 2019. doi:10.1145/3360555' apa: 'Huang, M., Fu, H., Chatterjee, K., & Goharshady, A. K. (2019). Modular verification for almost-sure termination of probabilistic programs. In Proceedings of the 34th ACM International Conference on Object-Oriented Programming, Systems, Languages, and Applications (Vol. 3). Athens, Greece: ACM. https://doi.org/10.1145/3360555' chicago: Huang, Mingzhang, Hongfei Fu, Krishnendu Chatterjee, and Amir Kafshdar Goharshady. “Modular Verification for Almost-Sure Termination of Probabilistic Programs.” In Proceedings of the 34th ACM International Conference on Object-Oriented Programming, Systems, Languages, and Applications , Vol. 3. ACM, 2019. https://doi.org/10.1145/3360555. ieee: M. Huang, H. Fu, K. Chatterjee, and A. K. Goharshady, “Modular verification for almost-sure termination of probabilistic programs,” in Proceedings of the 34th ACM International Conference on Object-Oriented Programming, Systems, Languages, and Applications , Athens, Greece, 2019, vol. 3. ista: 'Huang M, Fu H, Chatterjee K, Goharshady AK. 2019. Modular verification for almost-sure termination of probabilistic programs. Proceedings of the 34th ACM International Conference on Object-Oriented Programming, Systems, Languages, and Applications . OOPSLA: Object-oriented Programming, Systems, Languages and Applications vol. 3, 129.' mla: Huang, Mingzhang, et al. “Modular Verification for Almost-Sure Termination of Probabilistic Programs.” Proceedings of the 34th ACM International Conference on Object-Oriented Programming, Systems, Languages, and Applications , vol. 3, 129, ACM, 2019, doi:10.1145/3360555. short: M. Huang, H. Fu, K. Chatterjee, A.K. Goharshady, in:, Proceedings of the 34th ACM International Conference on Object-Oriented Programming, Systems, Languages, and Applications , ACM, 2019. conference: end_date: 2019-10-25 location: Athens, Greece name: 'OOPSLA: Object-oriented Programming, Systems, Languages and Applications' start_date: 2019-10-23 date_created: 2019-08-09T09:54:20Z date_published: 2019-10-01T00:00:00Z date_updated: 2026-05-14T22:31:18Z day: '01' ddc: - '000' department: - _id: KrCh doi: 10.1145/3360555 ec_funded: 1 external_id: arxiv: - '1901.06087' file: - access_level: open_access checksum: 3482d8ace6fb4991eb7810e3b70f1b9f content_type: application/pdf creator: akafshda date_created: 2019-08-12T15:40:57Z date_updated: 2020-07-14T12:47:40Z file_id: '6807' file_name: oopsla-2019.pdf file_size: 1024643 relation: main_file - access_level: open_access checksum: 4e5a6fb2b59a75222a4e8335a5a60eac content_type: application/pdf creator: dernst date_created: 2020-05-12T15:15:14Z date_updated: 2020-07-14T12:47:40Z file_id: '7821' file_name: 2019_ACM_Huang.pdf file_size: 538579 relation: main_file file_date_updated: 2020-07-14T12:47:40Z has_accepted_license: '1' intvolume: ' 3' language: - iso: eng month: '10' oa: 1 oa_version: Published Version project: - _id: 25892FC0-B435-11E9-9278-68D0E5697425 grant_number: ICT15-003 name: Efficient Algorithms for Computer Aided Verification - _id: 25863FF4-B435-11E9-9278-68D0E5697425 call_identifier: FWF grant_number: S11407 name: Game Theory - _id: 2581B60A-B435-11E9-9278-68D0E5697425 call_identifier: FP7 grant_number: '279307' name: 'Quantitative Graph Games: Theory and Applications' - _id: 267066CE-B435-11E9-9278-68D0E5697425 name: Quantitative Analysis of Probabilistic Systems with a focus on Crypto-Currencies - _id: 266EEEC0-B435-11E9-9278-68D0E5697425 name: Quantitative Game-theoretic Analysis of Blockchain Applications and Smart Contracts publication: 'Proceedings of the 34th ACM International Conference on Object-Oriented Programming, Systems, Languages, and Applications ' publication_status: published publisher: ACM quality_controlled: '1' related_material: record: - id: '8934' relation: dissertation_contains status: public scopus_import: '1' status: public title: Modular verification for almost-sure termination of probabilistic programs tmp: image: /images/cc_by_nc.png legal_code_url: https://creativecommons.org/licenses/by-nc/4.0/legalcode name: Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) short: CC BY-NC (4.0) type: conference user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9 volume: 3 year: '2019' ... --- _id: '6490' abstract: - lang: eng text: "Smart contracts are programs that are stored and executed on the Blockchain and can receive, manage and transfer money (cryptocurrency units). Two important problems regarding smart contracts are formal analysis and compiler optimization. Formal analysis is extremely important, because smart contracts hold funds worth billions of dollars and their code is immutable after deployment. Hence, an undetected bug can cause significant financial losses. Compiler optimization is also crucial, because every action of a smart contract has to be executed by every node in the Blockchain network. Therefore, optimizations in compiling smart contracts can lead to significant savings in computation, time and energy.\r\n\r\nTwo classical approaches in program analysis and compiler optimization are intraprocedural and interprocedural analysis. In intraprocedural analysis, each function is analyzed separately, while interprocedural analysis considers the entire program. In both cases, the analyses are usually reduced to graph problems over the control flow graph (CFG) of the program. These graph problems are often computationally expensive. Hence, there has been ample research on exploiting structural properties of CFGs for efficient algorithms. One such well-studied property is the treewidth, which is a measure of tree-likeness of graphs. It is known that intraprocedural CFGs of structured programs have treewidth at most 6, whereas the interprocedural treewidth cannot be bounded. This result has been used as a basis for many efficient intraprocedural analyses.\r\n\r\nIn this paper, we explore the idea of exploiting the treewidth of smart contracts for formal analysis and compiler optimization. First, similar to classical programs, we show that the intraprocedural treewidth of structured Solidity and Vyper smart contracts is at most 9. Second, for global analysis, we prove that the interprocedural treewidth of structured smart contracts is bounded by 10 and, in sharp contrast with classical programs, treewidth-based algorithms can be easily applied for interprocedural analysis. Finally, we supplement our theoretical results with experiments using a tool we implemented for computing treewidth of smart contracts and show that the treewidth is much lower in practice. We use 36,764 real-world Ethereum smart contracts as benchmarks and find that they have an average treewidth of at most 3.35 for the intraprocedural case and 3.65 for the interprocedural case.\r\n" article_processing_charge: No author: - first_name: Krishnendu full_name: Chatterjee, Krishnendu id: 2E5DCA20-F248-11E8-B48F-1D18A9856A87 last_name: Chatterjee orcid: 0000-0002-4561-241X - first_name: Amir Kafshdar full_name: Goharshady, Amir Kafshdar id: 391365CE-F248-11E8-B48F-1D18A9856A87 last_name: Goharshady orcid: 0000-0003-1702-6584 - first_name: Ehsan Kafshdar full_name: Goharshady, Ehsan Kafshdar last_name: Goharshady citation: ama: 'Chatterjee K, Goharshady AK, Goharshady EK. The treewidth of smart contracts. In: Proceedings of the 34th ACM Symposium on Applied Computing. Vol Part F147772. ACM; 2019:400-408. doi:10.1145/3297280.3297322' apa: 'Chatterjee, K., Goharshady, A. K., & Goharshady, E. K. (2019). The treewidth of smart contracts. In Proceedings of the 34th ACM Symposium on Applied Computing (Vol. Part F147772, pp. 400–408). Limassol, Cyprus: ACM. https://doi.org/10.1145/3297280.3297322' chicago: Chatterjee, Krishnendu, Amir Kafshdar Goharshady, and Ehsan Kafshdar Goharshady. “The Treewidth of Smart Contracts.” In Proceedings of the 34th ACM Symposium on Applied Computing, Part F147772:400–408. ACM, 2019. https://doi.org/10.1145/3297280.3297322. ieee: K. Chatterjee, A. K. Goharshady, and E. K. Goharshady, “The treewidth of smart contracts,” in Proceedings of the 34th ACM Symposium on Applied Computing, Limassol, Cyprus, 2019, vol. Part F147772, pp. 400–408. ista: 'Chatterjee K, Goharshady AK, Goharshady EK. 2019. The treewidth of smart contracts. Proceedings of the 34th ACM Symposium on Applied Computing. SAC: Symposium on Applied Computing vol. Part F147772, 400–408.' mla: Chatterjee, Krishnendu, et al. “The Treewidth of Smart Contracts.” Proceedings of the 34th ACM Symposium on Applied Computing, vol. Part F147772, ACM, 2019, pp. 400–08, doi:10.1145/3297280.3297322. short: K. Chatterjee, A.K. Goharshady, E.K. Goharshady, in:, Proceedings of the 34th ACM Symposium on Applied Computing, ACM, 2019, pp. 400–408. conference: end_date: 2019-04-12 location: Limassol, Cyprus name: 'SAC: Symposium on Applied Computing' start_date: 2019-04-08 corr_author: '1' date_created: 2019-05-26T21:59:15Z date_published: 2019-04-01T00:00:00Z date_updated: 2026-05-14T22:31:18Z day: '01' ddc: - '000' department: - _id: KrCh doi: 10.1145/3297280.3297322 external_id: isi: - '000474685800052' file: - access_level: open_access checksum: dddc20f6d9881f23b8755eb720ec9d6f content_type: application/pdf creator: dernst date_created: 2020-05-14T09:50:11Z date_updated: 2020-07-14T12:47:32Z file_id: '7827' file_name: 2019_ACM_Chatterjee.pdf file_size: 6937138 relation: main_file file_date_updated: 2020-07-14T12:47:32Z has_accepted_license: '1' isi: 1 language: - iso: eng month: '04' oa: 1 oa_version: Submitted Version page: 400-408 publication: Proceedings of the 34th ACM Symposium on Applied Computing publication_identifier: isbn: - '9781450359337' publication_status: published publisher: ACM pubrep_id: '1070' quality_controlled: '1' related_material: record: - id: '8934' relation: dissertation_contains status: public scopus_import: '1' status: public title: The treewidth of smart contracts type: conference user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: Part F147772 year: '2019' ... --- _id: '6378' abstract: - lang: eng text: 'In today''s cryptocurrencies, Hashcash proof of work is the most commonly-adopted approach to mining. In Hashcash, when a miner decides to add a block to the chain, she has to solve the difficult computational puzzle of inverting a hash function. While Hashcash has been successfully adopted in both Bitcoin and Ethereum, it has attracted significant and harsh criticism due to its massive waste of electricity, its carbon footprint and environmental effects, and the inherent lack of usefulness in inverting a hash function. Various other mining protocols have been suggested, including proof of stake, in which a miner''s chance of adding the next block is proportional to her current balance. However, such protocols lead to a higher entry cost for new miners who might not still have any stake in the cryptocurrency, and can in the worst case lead to an oligopoly, where the rich have complete control over mining. In this paper, we propose Hybrid Mining: a new mining protocol that combines solving real-world useful problems with Hashcash. Our protocol allows new miners to join the network by taking part in Hashcash mining without having to own an initial stake. It also allows nodes of the network to submit hard computational problems whose solutions are of interest in the real world, e.g.~protein folding problems. Then, miners can choose to compete in solving these problems, in lieu of Hashcash, for adding a new block. Hence, Hybrid Mining incentivizes miners to solve useful problems, such as hard computational problems arising in biology, in a distributed manner. It also gives researchers in other areas an easy-to-use tool to outsource their hard computations to the blockchain network, which has enormous computational power, by paying a reward to the miner who solves the problem for them. Moreover, our protocol provides strong security guarantees and is at least as resilient to double spending as Bitcoin.' article_processing_charge: No author: - first_name: Krishnendu full_name: Chatterjee, Krishnendu id: 2E5DCA20-F248-11E8-B48F-1D18A9856A87 last_name: Chatterjee orcid: 0000-0002-4561-241X - first_name: Amir Kafshdar full_name: Goharshady, Amir Kafshdar id: 391365CE-F248-11E8-B48F-1D18A9856A87 last_name: Goharshady orcid: 0000-0003-1702-6584 - first_name: Arash full_name: Pourdamghani, Arash last_name: Pourdamghani citation: ama: 'Chatterjee K, Goharshady AK, Pourdamghani A. Hybrid Mining: Exploiting blockchain’s computational power for distributed problem solving. In: Proceedings of the 34th ACM Symposium on Applied Computing. Vol Part F147772. ACM; 2019:374-381. doi:10.1145/3297280.3297319' apa: 'Chatterjee, K., Goharshady, A. K., & Pourdamghani, A. (2019). Hybrid Mining: Exploiting blockchain’s computational power for distributed problem solving. In Proceedings of the 34th ACM Symposium on Applied Computing (Vol. Part F147772, pp. 374–381). Limassol, Cyprus: ACM. https://doi.org/10.1145/3297280.3297319' chicago: 'Chatterjee, Krishnendu, Amir Kafshdar Goharshady, and Arash Pourdamghani. “Hybrid Mining: Exploiting Blockchain’s Computational Power for Distributed Problem Solving.” In Proceedings of the 34th ACM Symposium on Applied Computing, Part F147772:374–81. ACM, 2019. https://doi.org/10.1145/3297280.3297319.' ieee: 'K. Chatterjee, A. K. Goharshady, and A. Pourdamghani, “Hybrid Mining: Exploiting blockchain’s computational power for distributed problem solving,” in Proceedings of the 34th ACM Symposium on Applied Computing, Limassol, Cyprus, 2019, vol. Part F147772, pp. 374–381.' ista: 'Chatterjee K, Goharshady AK, Pourdamghani A. 2019. Hybrid Mining: Exploiting blockchain’s computational power for distributed problem solving. Proceedings of the 34th ACM Symposium on Applied Computing. ACM Symposium on Applied Computing vol. Part F147772, 374–381.' mla: 'Chatterjee, Krishnendu, et al. “Hybrid Mining: Exploiting Blockchain’s Computational Power for Distributed Problem Solving.” Proceedings of the 34th ACM Symposium on Applied Computing, vol. Part F147772, ACM, 2019, pp. 374–81, doi:10.1145/3297280.3297319.' short: K. Chatterjee, A.K. Goharshady, A. Pourdamghani, in:, Proceedings of the 34th ACM Symposium on Applied Computing, ACM, 2019, pp. 374–381. conference: end_date: 2019-04-12 location: Limassol, Cyprus name: ACM Symposium on Applied Computing start_date: 2019-04-08 date_created: 2019-05-06T12:11:36Z date_published: 2019-04-01T00:00:00Z date_updated: 2026-05-14T22:31:18Z day: '01' ddc: - '004' department: - _id: KrCh doi: 10.1145/3297280.3297319 ec_funded: 1 external_id: isi: - '000474685800049' file: - access_level: open_access checksum: fbfbcd5a0c7a743862bfc3045539a614 content_type: application/pdf creator: dernst date_created: 2019-05-06T12:09:27Z date_updated: 2020-07-14T12:47:29Z file_id: '6379' file_name: 2019_ACM_Chatterjee.pdf file_size: 1023934 relation: main_file file_date_updated: 2020-07-14T12:47:29Z has_accepted_license: '1' isi: 1 language: - iso: eng month: '04' oa: 1 oa_version: Submitted Version page: 374-381 project: - _id: 2581B60A-B435-11E9-9278-68D0E5697425 call_identifier: FP7 grant_number: '279307' name: 'Quantitative Graph Games: Theory and Applications' - _id: 25892FC0-B435-11E9-9278-68D0E5697425 grant_number: ICT15-003 name: Efficient Algorithms for Computer Aided Verification - _id: 25832EC2-B435-11E9-9278-68D0E5697425 call_identifier: FWF grant_number: S 11407_N23 name: Rigorous Systems Engineering publication: Proceedings of the 34th ACM Symposium on Applied Computing publication_identifier: isbn: - '9781450359337' publication_status: published publisher: ACM pubrep_id: '1069' quality_controlled: '1' related_material: record: - id: '8934' relation: dissertation_contains status: public scopus_import: '1' status: public title: 'Hybrid Mining: Exploiting blockchain’s computational power for distributed problem solving' type: conference user_id: 4359f0d1-fa6c-11eb-b949-802e58b17ae8 volume: Part F147772 year: '2019' ... --- _id: '6175' abstract: - lang: eng text: "We consider the problem of expected cost analysis over nondeterministic probabilistic programs,\r\nwhich aims at automated methods for analyzing the resource-usage of such programs.\r\nPrevious approaches for this problem could only handle nonnegative bounded costs.\r\nHowever, in many scenarios, such as queuing networks or analysis of cryptocurrency protocols,\r\nboth positive and negative costs are necessary and the costs are unbounded as well.\r\n\r\nIn this work, we present a sound and efficient approach to obtain polynomial bounds on the\r\nexpected accumulated cost of nondeterministic probabilistic programs.\r\nOur approach can handle (a) general positive and negative costs with bounded updates in\r\nvariables; and (b) nonnegative costs with general updates to variables.\r\nWe show that several natural examples which could not be\r\nhandled by previous approaches are captured in our framework.\r\n\r\nMoreover, our approach leads to an efficient polynomial-time algorithm, while no\r\nprevious approach for cost analysis of probabilistic programs could guarantee polynomial runtime.\r\nFinally, we show the effectiveness of our approach using experimental results on a variety of programs for which we efficiently synthesize tight resource-usage bounds." article_processing_charge: No arxiv: 1 author: - first_name: Peixin full_name: Wang, Peixin last_name: Wang - first_name: Hongfei full_name: Fu, Hongfei id: 3AAD03D6-F248-11E8-B48F-1D18A9856A87 last_name: Fu - first_name: Amir Kafshdar full_name: Goharshady, Amir Kafshdar id: 391365CE-F248-11E8-B48F-1D18A9856A87 last_name: Goharshady orcid: 0000-0003-1702-6584 - first_name: Krishnendu full_name: Chatterjee, Krishnendu id: 2E5DCA20-F248-11E8-B48F-1D18A9856A87 last_name: Chatterjee orcid: 0000-0002-4561-241X - first_name: Xudong full_name: Qin, Xudong last_name: Qin - first_name: Wenjun full_name: Shi, Wenjun last_name: Shi citation: ama: 'Wang P, Fu H, Goharshady AK, Chatterjee K, Qin X, Shi W. Cost analysis of nondeterministic probabilistic programs. In: PLDI 2019: Proceedings of the 40th ACM SIGPLAN Conference on Programming Language Design and Implementation. Association for Computing Machinery; 2019:204-220. doi:10.1145/3314221.3314581' apa: 'Wang, P., Fu, H., Goharshady, A. K., Chatterjee, K., Qin, X., & Shi, W. (2019). Cost analysis of nondeterministic probabilistic programs. In PLDI 2019: Proceedings of the 40th ACM SIGPLAN Conference on Programming Language Design and Implementation (pp. 204–220). Phoenix, AZ, United States: Association for Computing Machinery. https://doi.org/10.1145/3314221.3314581' chicago: 'Wang, Peixin, Hongfei Fu, Amir Kafshdar Goharshady, Krishnendu Chatterjee, Xudong Qin, and Wenjun Shi. “Cost Analysis of Nondeterministic Probabilistic Programs.” In PLDI 2019: Proceedings of the 40th ACM SIGPLAN Conference on Programming Language Design and Implementation, 204–20. Association for Computing Machinery, 2019. https://doi.org/10.1145/3314221.3314581.' ieee: 'P. Wang, H. Fu, A. K. Goharshady, K. Chatterjee, X. Qin, and W. Shi, “Cost analysis of nondeterministic probabilistic programs,” in PLDI 2019: Proceedings of the 40th ACM SIGPLAN Conference on Programming Language Design and Implementation, Phoenix, AZ, United States, 2019, pp. 204–220.' ista: 'Wang P, Fu H, Goharshady AK, Chatterjee K, Qin X, Shi W. 2019. Cost analysis of nondeterministic probabilistic programs. PLDI 2019: Proceedings of the 40th ACM SIGPLAN Conference on Programming Language Design and Implementation. PLDI: Conference on Programming Language Design and Implementation, 204–220.' mla: 'Wang, Peixin, et al. “Cost Analysis of Nondeterministic Probabilistic Programs.” PLDI 2019: Proceedings of the 40th ACM SIGPLAN Conference on Programming Language Design and Implementation, Association for Computing Machinery, 2019, pp. 204–20, doi:10.1145/3314221.3314581.' short: 'P. Wang, H. Fu, A.K. Goharshady, K. Chatterjee, X. Qin, W. Shi, in:, PLDI 2019: Proceedings of the 40th ACM SIGPLAN Conference on Programming Language Design and Implementation, Association for Computing Machinery, 2019, pp. 204–220.' conference: end_date: 2019-06-26 location: Phoenix, AZ, United States name: 'PLDI: Conference on Programming Language Design and Implementation' start_date: 2019-06-22 date_created: 2019-03-25T10:13:25Z date_published: 2019-06-08T00:00:00Z date_updated: 2026-05-14T22:31:18Z day: '08' ddc: - '000' department: - _id: KrCh doi: 10.1145/3314221.3314581 ec_funded: 1 external_id: arxiv: - '1902.04659' isi: - '000523190300014' file: - access_level: open_access checksum: 703a5e9b8c8587f2a44085ffd9a4db64 content_type: application/pdf creator: akafshda date_created: 2019-03-25T10:11:22Z date_updated: 2020-07-14T12:47:20Z file_id: '6176' file_name: paper.pdf file_size: 4051066 relation: main_file file_date_updated: 2020-07-14T12:47:20Z has_accepted_license: '1' isi: 1 keyword: - Program Cost Analysis - Program Termination - Probabilistic Programs - Martingales language: - iso: eng month: '06' oa: 1 oa_version: Submitted Version page: 204-220 project: - _id: 25892FC0-B435-11E9-9278-68D0E5697425 grant_number: ICT15-003 name: Efficient Algorithms for Computer Aided Verification - _id: 25863FF4-B435-11E9-9278-68D0E5697425 call_identifier: FWF grant_number: S11407 name: Game Theory - _id: 25832EC2-B435-11E9-9278-68D0E5697425 call_identifier: FWF grant_number: S 11407_N23 name: Rigorous Systems Engineering - _id: 2581B60A-B435-11E9-9278-68D0E5697425 call_identifier: FP7 grant_number: '279307' name: 'Quantitative Graph Games: Theory and Applications' - _id: 266EEEC0-B435-11E9-9278-68D0E5697425 name: Quantitative Game-theoretic Analysis of Blockchain Applications and Smart Contracts publication: 'PLDI 2019: Proceedings of the 40th ACM SIGPLAN Conference on Programming Language Design and Implementation' publication_status: published publisher: Association for Computing Machinery quality_controlled: '1' related_material: record: - id: '5457' relation: earlier_version status: public - id: '8934' relation: dissertation_contains status: public scopus_import: '1' status: public title: Cost analysis of nondeterministic probabilistic programs type: conference user_id: 4359f0d1-fa6c-11eb-b949-802e58b17ae8 year: '2019' ... --- _id: '7158' abstract: - lang: eng text: "Interprocedural analysis is at the heart of numerous applications in programming languages, such as alias analysis, constant propagation, and so on. Recursive state machines (RSMs) are standard models for interprocedural analysis. We consider a general framework with RSMs where the transitions are labeled from a semiring and path properties are algebraic with semiring operations. RSMs with algebraic path properties can model interprocedural dataflow analysis problems, the shortest path problem, the most probable path problem, and so on. The traditional algorithms for interprocedural analysis focus on path properties where the starting point is fixed as the entry point of a specific method. In this work, we consider possible multiple queries as required in many applications such as in alias analysis. The study of multiple queries allows us to bring in an important algorithmic distinction between the resource usage of the one-time preprocessing vs for each individual query. The second aspect we consider is that the control flow graphs for most programs have constant treewidth.\r\n\r\nOur main contributions are simple and implementable algorithms that support multiple queries for algebraic path properties for RSMs that have constant treewidth. Our theoretical results show that our algorithms have small additional one-time preprocessing but can answer subsequent queries significantly faster as compared to the current algorithmic solutions for interprocedural dataflow analysis. We have also implemented our algorithms and evaluated their performance for performing on-demand interprocedural dataflow analysis on various domains, such as for live variable analysis and reaching definitions, on a standard benchmark set. Our experimental results align with our theoretical statements and show that after a lightweight preprocessing, on-demand queries are answered much faster than the standard existing algorithmic approaches.\r\n" article_number: '23' article_processing_charge: No article_type: original author: - first_name: Krishnendu full_name: Chatterjee, Krishnendu id: 2E5DCA20-F248-11E8-B48F-1D18A9856A87 last_name: Chatterjee orcid: 0000-0002-4561-241X - first_name: Amir Kafshdar full_name: Goharshady, Amir Kafshdar id: 391365CE-F248-11E8-B48F-1D18A9856A87 last_name: Goharshady orcid: 0000-0003-1702-6584 - first_name: Prateesh full_name: Goyal, Prateesh last_name: Goyal - first_name: Rasmus full_name: Ibsen-Jensen, Rasmus id: 3B699956-F248-11E8-B48F-1D18A9856A87 last_name: Ibsen-Jensen orcid: 0000-0003-4783-0389 - first_name: Andreas full_name: Pavlogiannis, Andreas id: 49704004-F248-11E8-B48F-1D18A9856A87 last_name: Pavlogiannis orcid: 0000-0002-8943-0722 citation: ama: Chatterjee K, Goharshady AK, Goyal P, Ibsen-Jensen R, Pavlogiannis A. Faster algorithms for dynamic algebraic queries in basic RSMs with constant treewidth. ACM Transactions on Programming Languages and Systems. 2019;41(4). doi:10.1145/3363525 apa: Chatterjee, K., Goharshady, A. K., Goyal, P., Ibsen-Jensen, R., & Pavlogiannis, A. (2019). Faster algorithms for dynamic algebraic queries in basic RSMs with constant treewidth. ACM Transactions on Programming Languages and Systems. ACM. https://doi.org/10.1145/3363525 chicago: Chatterjee, Krishnendu, Amir Kafshdar Goharshady, Prateesh Goyal, Rasmus Ibsen-Jensen, and Andreas Pavlogiannis. “Faster Algorithms for Dynamic Algebraic Queries in Basic RSMs with Constant Treewidth.” ACM Transactions on Programming Languages and Systems. ACM, 2019. https://doi.org/10.1145/3363525. ieee: K. Chatterjee, A. K. Goharshady, P. Goyal, R. Ibsen-Jensen, and A. Pavlogiannis, “Faster algorithms for dynamic algebraic queries in basic RSMs with constant treewidth,” ACM Transactions on Programming Languages and Systems, vol. 41, no. 4. ACM, 2019. ista: Chatterjee K, Goharshady AK, Goyal P, Ibsen-Jensen R, Pavlogiannis A. 2019. Faster algorithms for dynamic algebraic queries in basic RSMs with constant treewidth. ACM Transactions on Programming Languages and Systems. 41(4), 23. mla: Chatterjee, Krishnendu, et al. “Faster Algorithms for Dynamic Algebraic Queries in Basic RSMs with Constant Treewidth.” ACM Transactions on Programming Languages and Systems, vol. 41, no. 4, 23, ACM, 2019, doi:10.1145/3363525. short: K. Chatterjee, A.K. Goharshady, P. Goyal, R. Ibsen-Jensen, A. Pavlogiannis, ACM Transactions on Programming Languages and Systems 41 (2019). date_created: 2019-12-09T08:33:33Z date_published: 2019-11-01T00:00:00Z date_updated: 2026-05-14T22:31:18Z day: '01' ddc: - '000' department: - _id: KrCh doi: 10.1145/3363525 ec_funded: 1 external_id: isi: - '000564108400004' file: - access_level: open_access checksum: 291cc86a07bd010d4815e177dac57b70 content_type: application/pdf creator: dernst date_created: 2020-10-08T12:58:10Z date_updated: 2020-10-08T12:58:10Z file_id: '8632' file_name: 2019_ACMTransactions_Chatterjee.pdf file_size: 667357 relation: main_file success: 1 file_date_updated: 2020-10-08T12:58:10Z has_accepted_license: '1' intvolume: ' 41' isi: 1 issue: '4' language: - iso: eng month: '11' oa: 1 oa_version: Submitted Version project: - _id: 2584A770-B435-11E9-9278-68D0E5697425 call_identifier: FWF grant_number: P 23499-N23 name: Modern Graph Algorithmic Techniques in Formal Verification - _id: 25863FF4-B435-11E9-9278-68D0E5697425 call_identifier: FWF grant_number: S11407 name: Game Theory - _id: 2581B60A-B435-11E9-9278-68D0E5697425 call_identifier: FP7 grant_number: '279307' name: 'Quantitative Graph Games: Theory and Applications' publication: ACM Transactions on Programming Languages and Systems publication_identifier: issn: - 0164-0925 publication_status: published publisher: ACM quality_controlled: '1' related_material: record: - id: '8934' relation: dissertation_contains status: public scopus_import: '1' status: public title: Faster algorithms for dynamic algebraic queries in basic RSMs with constant treewidth type: journal_article user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1 volume: 41 year: '2019' ... --- _id: '7014' abstract: - lang: eng text: "We study the problem of developing efficient approaches for proving\r\nworst-case bounds of non-deterministic recursive programs. Ranking functions\r\nare sound and complete for proving termination and worst-case bounds of\r\nnonrecursive programs. First, we apply ranking functions to recursion,\r\nresulting in measure functions. We show that measure functions provide a sound\r\nand complete approach to prove worst-case bounds of non-deterministic recursive\r\nprograms. Our second contribution is the synthesis of measure functions in\r\nnonpolynomial forms. We show that non-polynomial measure functions with\r\nlogarithm and exponentiation can be synthesized through abstraction of\r\nlogarithmic or exponentiation terms, Farkas' Lemma, and Handelman's Theorem\r\nusing linear programming. While previous methods obtain worst-case polynomial\r\nbounds, our approach can synthesize bounds of the form $\\mathcal{O}(n\\log n)$\r\nas well as $\\mathcal{O}(n^r)$ where $r$ is not an integer. We present\r\nexperimental results to demonstrate that our approach can obtain efficiently\r\nworst-case bounds of classical recursive algorithms such as (i) Merge-Sort, the\r\ndivide-and-conquer algorithm for the Closest-Pair problem, where we obtain\r\n$\\mathcal{O}(n \\log n)$ worst-case bound, and (ii) Karatsuba's algorithm for\r\npolynomial multiplication and Strassen's algorithm for matrix multiplication,\r\nwhere we obtain $\\mathcal{O}(n^r)$ bound such that $r$ is not an integer and\r\nclose to the best-known bounds for the respective algorithms." article_number: '20' article_processing_charge: No article_type: original arxiv: 1 author: - first_name: Krishnendu full_name: Chatterjee, Krishnendu id: 2E5DCA20-F248-11E8-B48F-1D18A9856A87 last_name: Chatterjee orcid: 0000-0002-4561-241X - first_name: Hongfei full_name: Fu, Hongfei last_name: Fu - first_name: Amir Kafshdar full_name: Goharshady, Amir Kafshdar id: 391365CE-F248-11E8-B48F-1D18A9856A87 last_name: Goharshady orcid: 0000-0003-1702-6584 citation: ama: Chatterjee K, Fu H, Goharshady AK. Non-polynomial worst-case analysis of recursive programs. ACM Transactions on Programming Languages and Systems. 2019;41(4). doi:10.1145/3339984 apa: Chatterjee, K., Fu, H., & Goharshady, A. K. (2019). Non-polynomial worst-case analysis of recursive programs. ACM Transactions on Programming Languages and Systems. ACM. https://doi.org/10.1145/3339984 chicago: Chatterjee, Krishnendu, Hongfei Fu, and Amir Kafshdar Goharshady. “Non-Polynomial Worst-Case Analysis of Recursive Programs.” ACM Transactions on Programming Languages and Systems. ACM, 2019. https://doi.org/10.1145/3339984. ieee: K. Chatterjee, H. Fu, and A. K. Goharshady, “Non-polynomial worst-case analysis of recursive programs,” ACM Transactions on Programming Languages and Systems, vol. 41, no. 4. ACM, 2019. ista: Chatterjee K, Fu H, Goharshady AK. 2019. Non-polynomial worst-case analysis of recursive programs. ACM Transactions on Programming Languages and Systems. 41(4), 20. mla: Chatterjee, Krishnendu, et al. “Non-Polynomial Worst-Case Analysis of Recursive Programs.” ACM Transactions on Programming Languages and Systems, vol. 41, no. 4, 20, ACM, 2019, doi:10.1145/3339984. short: K. Chatterjee, H. Fu, A.K. Goharshady, ACM Transactions on Programming Languages and Systems 41 (2019). date_created: 2019-11-13T08:33:43Z date_published: 2019-10-01T00:00:00Z date_updated: 2026-05-14T22:31:19Z day: '01' department: - _id: KrCh doi: 10.1145/3339984 ec_funded: 1 external_id: arxiv: - '1705.00317' isi: - '000564108400001' intvolume: ' 41' isi: 1 issue: '4' language: - iso: eng main_file_link: - open_access: '1' url: https://arxiv.org/abs/1705.00317 month: '10' oa: 1 oa_version: Preprint project: - _id: 25892FC0-B435-11E9-9278-68D0E5697425 grant_number: ICT15-003 name: Efficient Algorithms for Computer Aided Verification - _id: 25832EC2-B435-11E9-9278-68D0E5697425 call_identifier: FWF grant_number: S 11407_N23 name: Rigorous Systems Engineering - _id: 2581B60A-B435-11E9-9278-68D0E5697425 call_identifier: FP7 grant_number: '279307' name: 'Quantitative Graph Games: Theory and Applications' - _id: 267066CE-B435-11E9-9278-68D0E5697425 name: Quantitative Analysis of Probabilistic Systems with a focus on Crypto-Currencies - _id: 266EEEC0-B435-11E9-9278-68D0E5697425 name: Quantitative Game-theoretic Analysis of Blockchain Applications and Smart Contracts publication: ACM Transactions on Programming Languages and Systems publication_status: published publisher: ACM quality_controlled: '1' related_material: record: - id: '639' relation: earlier_version status: public - id: '8934' relation: dissertation_contains status: public scopus_import: '1' status: public title: Non-polynomial worst-case analysis of recursive programs type: journal_article user_id: 4359f0d1-fa6c-11eb-b949-802e58b17ae8 volume: 41 year: '2019' ... --- OA_place: publisher OA_type: hybrid _id: '6380' abstract: - lang: eng text: 'There is a huge gap between the speeds of modern caches and main memories, and therefore cache misses account for a considerable loss of efficiency in programs. The predominant technique to address this issue has been Data Packing: data elements that are frequently accessed within time proximity are packed into the same cache block, thereby minimizing accesses to the main memory. We consider the algorithmic problem of Data Packing on a two-level memory system. Given a reference sequence R of accesses to data elements, the task is to partition the elements into cache blocks such that the number of cache misses on R is minimized. The problem is notoriously difficult: it is NP-hard even when the cache has size 1, and is hard to approximate for any cache size larger than 4. Therefore, all existing techniques for Data Packing are based on heuristics and lack theoretical guarantees. In this work, we present the first positive theoretical results for Data Packing, along with new and stronger negative results. We consider the problem under the lens of the underlying access hypergraphs, which are hypergraphs of affinities between the data elements, where the order of an access hypergraph corresponds to the size of the affinity group. We study the problem parameterized by the treewidth of access hypergraphs, which is a standard notion in graph theory to measure the closeness of a graph to a tree. Our main results are as follows: We show there is a number q* depending on the cache parameters such that (a) if the access hypergraph of order q* has constant treewidth, then there is a linear-time algorithm for Data Packing; (b)the Data Packing problem remains NP-hard even if the access hypergraph of order q*-1 has constant treewidth. Thus, we establish a fine-grained dichotomy depending on a single parameter, namely, the highest order among access hypegraphs that have constant treewidth; and establish the optimal value q* of this parameter. Finally, we present an experimental evaluation of a prototype implementation of our algorithm. Our results demonstrate that, in practice, access hypergraphs of many commonly-used algorithms have small treewidth. We compare our approach with several state-of-the-art heuristic-based algorithms and show that our algorithm leads to significantly fewer cache-misses. ' acknowledgement: "The research was partially supported by Vienna Science and Technology Fund (WWTF) Project ICT15-003, Austrian Science Fund (FWF) NFN Grant No S11407-N23 (RiSE/SHiNE), ERC\r\nStarting Grant (279307: Graph Games), and the IBM PhD Fellowship program." article_number: '53' article_processing_charge: Yes (in subscription journal) article_type: original author: - first_name: Krishnendu full_name: Chatterjee, Krishnendu id: 2E5DCA20-F248-11E8-B48F-1D18A9856A87 last_name: Chatterjee orcid: 0000-0002-4561-241X - first_name: Amir Kafshdar full_name: Goharshady, Amir Kafshdar id: 391365CE-F248-11E8-B48F-1D18A9856A87 last_name: Goharshady orcid: 0000-0003-1702-6584 - first_name: Nastaran full_name: Okati, Nastaran last_name: Okati - first_name: Andreas full_name: Pavlogiannis, Andreas id: 49704004-F248-11E8-B48F-1D18A9856A87 last_name: Pavlogiannis orcid: 0000-0002-8943-0722 citation: ama: Chatterjee K, Goharshady AK, Okati N, Pavlogiannis A. Efficient parameterized algorithms for data packing. Proceedings of the ACM on Programming Languages. 2019;3(POPL). doi:10.1145/3290366 apa: Chatterjee, K., Goharshady, A. K., Okati, N., & Pavlogiannis, A. (2019). Efficient parameterized algorithms for data packing. Proceedings of the ACM on Programming Languages. ACM. https://doi.org/10.1145/3290366 chicago: Chatterjee, Krishnendu, Amir Kafshdar Goharshady, Nastaran Okati, and Andreas Pavlogiannis. “Efficient Parameterized Algorithms for Data Packing.” Proceedings of the ACM on Programming Languages. ACM, 2019. https://doi.org/10.1145/3290366. ieee: K. Chatterjee, A. K. Goharshady, N. Okati, and A. Pavlogiannis, “Efficient parameterized algorithms for data packing,” Proceedings of the ACM on Programming Languages, vol. 3, no. POPL. ACM, 2019. ista: Chatterjee K, Goharshady AK, Okati N, Pavlogiannis A. 2019. Efficient parameterized algorithms for data packing. Proceedings of the ACM on Programming Languages. 3(POPL), 53. mla: Chatterjee, Krishnendu, et al. “Efficient Parameterized Algorithms for Data Packing.” Proceedings of the ACM on Programming Languages, vol. 3, no. POPL, 53, ACM, 2019, doi:10.1145/3290366. short: K. Chatterjee, A.K. Goharshady, N. Okati, A. Pavlogiannis, Proceedings of the ACM on Programming Languages 3 (2019). date_created: 2019-05-06T12:18:17Z date_published: 2019-01-01T00:00:00Z date_updated: 2026-05-14T22:31:19Z day: '01' ddc: - '004' department: - _id: KrCh doi: 10.1145/3290366 ec_funded: 1 file: - access_level: open_access checksum: c157752f96877b36685ad7063ada4524 content_type: application/pdf creator: dernst date_created: 2019-05-06T12:23:11Z date_updated: 2020-07-14T12:47:29Z file_id: '6381' file_name: 2019_ACM_POPL_Chatterjee.pdf file_size: 1294962 relation: main_file file_date_updated: 2020-07-14T12:47:29Z has_accepted_license: '1' intvolume: ' 3' issue: POPL language: - iso: eng month: '01' oa: 1 oa_version: Published Version project: - _id: 25892FC0-B435-11E9-9278-68D0E5697425 grant_number: ICT15-003 name: Efficient Algorithms for Computer Aided Verification - _id: 25832EC2-B435-11E9-9278-68D0E5697425 call_identifier: FWF grant_number: S 11407_N23 name: Rigorous Systems Engineering - _id: 2581B60A-B435-11E9-9278-68D0E5697425 call_identifier: FP7 grant_number: '279307' name: 'Quantitative Graph Games: Theory and Applications' publication: Proceedings of the ACM on Programming Languages publication_identifier: issn: - 2475-1421 publication_status: published publisher: ACM pubrep_id: '1056' quality_controlled: '1' related_material: record: - id: '8934' relation: dissertation_contains status: public scopus_import: '1' status: public title: Efficient parameterized algorithms for data packing tmp: image: /images/cc_by.png legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0) short: CC BY (4.0) type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 3 year: '2019' ... --- _id: '6056' abstract: - lang: eng text: In today's programmable blockchains, smart contracts are limited to being deterministic and non-probabilistic. This lack of randomness is a consequential limitation, given that a wide variety of real-world financial contracts, such as casino games and lotteries, depend entirely on randomness. As a result, several ad-hoc random number generation approaches have been developed to be used in smart contracts. These include ideas such as using an oracle or relying on the block hash. However, these approaches are manipulatable, i.e. their output can be tampered with by parties who might not be neutral, such as the owner of the oracle or the miners.We propose a novel game-theoretic approach for generating provably unmanipulatable pseudorandom numbers on the blockchain. Our approach allows smart contracts to access a trustworthy source of randomness that does not rely on potentially compromised miners or oracles, hence enabling the creation of a new generation of smart contracts that are not limited to being non-probabilistic and can be drawn from the much more general class of probabilistic programs. article_number: '8751326' article_processing_charge: No arxiv: 1 author: - first_name: Krishnendu full_name: Chatterjee, Krishnendu id: 2E5DCA20-F248-11E8-B48F-1D18A9856A87 last_name: Chatterjee orcid: 0000-0002-4561-241X - first_name: Amir Kafshdar full_name: Goharshady, Amir Kafshdar id: 391365CE-F248-11E8-B48F-1D18A9856A87 last_name: Goharshady orcid: 0000-0003-1702-6584 - first_name: Arash full_name: Pourdamghani, Arash last_name: Pourdamghani citation: ama: 'Chatterjee K, Goharshady AK, Pourdamghani A. Probabilistic smart contracts: Secure randomness on the blockchain. In: IEEE International Conference on Blockchain and Cryptocurrency. IEEE; 2019. doi:10.1109/BLOC.2019.8751326' apa: 'Chatterjee, K., Goharshady, A. K., & Pourdamghani, A. (2019). Probabilistic smart contracts: Secure randomness on the blockchain. In IEEE International Conference on Blockchain and Cryptocurrency. Seoul, Korea: IEEE. https://doi.org/10.1109/BLOC.2019.8751326' chicago: 'Chatterjee, Krishnendu, Amir Kafshdar Goharshady, and Arash Pourdamghani. “Probabilistic Smart Contracts: Secure Randomness on the Blockchain.” In IEEE International Conference on Blockchain and Cryptocurrency. IEEE, 2019. https://doi.org/10.1109/BLOC.2019.8751326.' ieee: 'K. Chatterjee, A. K. Goharshady, and A. Pourdamghani, “Probabilistic smart contracts: Secure randomness on the blockchain,” in IEEE International Conference on Blockchain and Cryptocurrency, Seoul, Korea, 2019.' ista: 'Chatterjee K, Goharshady AK, Pourdamghani A. 2019. Probabilistic smart contracts: Secure randomness on the blockchain. IEEE International Conference on Blockchain and Cryptocurrency. IEEE International Conference on Blockchain and Cryptocurrency, 8751326.' mla: 'Chatterjee, Krishnendu, et al. “Probabilistic Smart Contracts: Secure Randomness on the Blockchain.” IEEE International Conference on Blockchain and Cryptocurrency, 8751326, IEEE, 2019, doi:10.1109/BLOC.2019.8751326.' short: K. Chatterjee, A.K. Goharshady, A. Pourdamghani, in:, IEEE International Conference on Blockchain and Cryptocurrency, IEEE, 2019. conference: end_date: 2019-05-17 location: Seoul, Korea name: IEEE International Conference on Blockchain and Cryptocurrency start_date: 2019-05-14 date_created: 2019-02-26T09:03:15Z date_published: 2019-05-01T00:00:00Z date_updated: 2026-05-14T22:31:19Z day: '01' department: - _id: KrCh doi: 10.1109/BLOC.2019.8751326 ec_funded: 1 external_id: arxiv: - '1902.07986' isi: - '000491257000076' isi: 1 language: - iso: eng main_file_link: - open_access: '1' url: https://arxiv.org/abs/1902.07986 month: '05' oa: 1 oa_version: Preprint project: - _id: 25892FC0-B435-11E9-9278-68D0E5697425 grant_number: ICT15-003 name: Efficient Algorithms for Computer Aided Verification - _id: 25832EC2-B435-11E9-9278-68D0E5697425 call_identifier: FWF grant_number: S 11407_N23 name: Rigorous Systems Engineering - _id: 2581B60A-B435-11E9-9278-68D0E5697425 call_identifier: FP7 grant_number: '279307' name: 'Quantitative Graph Games: Theory and Applications' - _id: 266EEEC0-B435-11E9-9278-68D0E5697425 name: Quantitative Game-theoretic Analysis of Blockchain Applications and Smart Contracts - _id: 267066CE-B435-11E9-9278-68D0E5697425 name: Quantitative Analysis of Probabilistic Systems with a focus on Crypto-Currencies publication: IEEE International Conference on Blockchain and Cryptocurrency publication_status: published publisher: IEEE quality_controlled: '1' related_material: record: - id: '8934' relation: dissertation_contains status: public scopus_import: '1' status: public title: 'Probabilistic smart contracts: Secure randomness on the blockchain' type: conference user_id: 317138e5-6ab7-11ef-aa6d-ffef3953e345 year: '2019' ... --- _id: '6627' abstract: - lang: eng text: Cortical microtubule arrays in elongating epidermal cells in both the root and stem of plants have the propensity of dynamic reorientations that are correlated with the activation or inhibition of growth. Factors regulating plant growth, among them the hormone auxin, have been recognized as regulators of microtubule array orientations. Some previous work in the field has aimed at elucidating the causal relationship between cell growth, the signaling of auxin or other growth-regulating factors, and microtubule array reorientations, with various conclusions. Here, we revisit this problem of causality with a comprehensive set of experiments in Arabidopsis thaliana, using the now available pharmacological and genetic tools. We use isolated, auxin-depleted hypocotyls, an experimental system allowing for full control of both growth and auxin signaling. We demonstrate that reorientation of microtubules is not directly triggered by an auxin signal during growth activation. Instead, reorientation is triggered by the activation of the growth process itself and is auxin-independent in its nature. We discuss these findings in the context of previous relevant work, including that on the mechanical regulation of microtubule array orientation. article_number: '3337' article_processing_charge: Yes article_type: original author: - first_name: Maciek full_name: Adamowski, Maciek id: 45F536D2-F248-11E8-B48F-1D18A9856A87 last_name: Adamowski orcid: 0000-0001-6463-5257 - first_name: Lanxin full_name: Li, Lanxin id: 367EF8FA-F248-11E8-B48F-1D18A9856A87 last_name: Li orcid: 0000-0002-5607-272X - first_name: Jiří full_name: Friml, Jiří id: 4159519E-F248-11E8-B48F-1D18A9856A87 last_name: Friml orcid: 0000-0002-8302-7596 citation: ama: Adamowski M, Li L, Friml J. Reorientation of cortical microtubule arrays in the hypocotyl of arabidopsis thaliana is induced by the cell growth process and independent of auxin signaling. International Journal of Molecular Sciences. 2019;20(13). doi:10.3390/ijms20133337 apa: Adamowski, M., Li, L., & Friml, J. (2019). Reorientation of cortical microtubule arrays in the hypocotyl of arabidopsis thaliana is induced by the cell growth process and independent of auxin signaling. International Journal of Molecular Sciences. MDPI. https://doi.org/10.3390/ijms20133337 chicago: Adamowski, Maciek, Lanxin Li, and Jiří Friml. “Reorientation of Cortical Microtubule Arrays in the Hypocotyl of Arabidopsis Thaliana Is Induced by the Cell Growth Process and Independent of Auxin Signaling.” International Journal of Molecular Sciences. MDPI, 2019. https://doi.org/10.3390/ijms20133337. ieee: M. Adamowski, L. Li, and J. Friml, “Reorientation of cortical microtubule arrays in the hypocotyl of arabidopsis thaliana is induced by the cell growth process and independent of auxin signaling,” International Journal of Molecular Sciences, vol. 20, no. 13. MDPI, 2019. ista: Adamowski M, Li L, Friml J. 2019. Reorientation of cortical microtubule arrays in the hypocotyl of arabidopsis thaliana is induced by the cell growth process and independent of auxin signaling. International Journal of Molecular Sciences. 20(13), 3337. mla: Adamowski, Maciek, et al. “Reorientation of Cortical Microtubule Arrays in the Hypocotyl of Arabidopsis Thaliana Is Induced by the Cell Growth Process and Independent of Auxin Signaling.” International Journal of Molecular Sciences, vol. 20, no. 13, 3337, MDPI, 2019, doi:10.3390/ijms20133337. short: M. Adamowski, L. Li, J. Friml, International Journal of Molecular Sciences 20 (2019). corr_author: '1' date_created: 2019-07-11T12:00:32Z date_published: 2019-07-07T00:00:00Z date_updated: 2026-05-14T22:31:21Z day: '07' ddc: - '580' department: - _id: JiFr doi: 10.3390/ijms20133337 ec_funded: 1 external_id: isi: - '000477041100221' pmid: - '31284661' file: - access_level: open_access checksum: dd9d1cbb933a72ceb666c9667890ac51 content_type: application/pdf creator: dernst date_created: 2019-07-17T06:17:15Z date_updated: 2020-07-14T12:47:34Z file_id: '6645' file_name: 2019_JournalMolecularScience_Adamowski.pdf file_size: 3330291 relation: main_file file_date_updated: 2020-07-14T12:47:34Z has_accepted_license: '1' intvolume: ' 20' isi: 1 issue: '13' language: - iso: eng month: '07' oa: 1 oa_version: Published Version pmid: 1 project: - _id: 25716A02-B435-11E9-9278-68D0E5697425 call_identifier: FP7 grant_number: '282300' name: Polarity and subcellular dynamics in plants - _id: 2564DBCA-B435-11E9-9278-68D0E5697425 call_identifier: H2020 grant_number: '665385' name: International IST Doctoral Program - _id: B67AFEDC-15C9-11EA-A837-991A96BB2854 name: IST Austria Open Access Fund publication: International Journal of Molecular Sciences publication_identifier: eissn: - 1422-0067 publication_status: published publisher: MDPI quality_controlled: '1' related_material: record: - id: '10083' relation: dissertation_contains status: public scopus_import: '1' status: public title: Reorientation of cortical microtubule arrays in the hypocotyl of arabidopsis thaliana is induced by the cell growth process and independent of auxin signaling tmp: image: /images/cc_by.png legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0) short: CC BY (4.0) type: journal_article user_id: 4359f0d1-fa6c-11eb-b949-802e58b17ae8 volume: 20 year: '2019' ... --- _id: '6609' abstract: - lang: eng text: Mechanical systems facilitate the development of a hybrid quantum technology comprising electrical, optical, atomic and acoustic degrees of freedom1, and entanglement is essential to realize quantum-enabled devices. Continuous-variable entangled fields—known as Einstein–Podolsky–Rosen (EPR) states—are spatially separated two-mode squeezed states that can be used for quantum teleportation and quantum communication2. In the optical domain, EPR states are typically generated using nondegenerate optical amplifiers3, and at microwave frequencies Josephson circuits can serve as a nonlinear medium4,5,6. An outstanding goal is to deterministically generate and distribute entangled states with a mechanical oscillator, which requires a carefully arranged balance between excitation, cooling and dissipation in an ultralow noise environment. Here we observe stationary emission of path-entangled microwave radiation from a parametrically driven 30-micrometre-long silicon nanostring oscillator, squeezing the joint field operators of two thermal modes by 3.40 decibels below the vacuum level. The motion of this micromechanical system correlates up to 50 photons per second per hertz, giving rise to a quantum discord that is robust with respect to microwave noise7. Such generalized quantum correlations of separable states are important for quantum-enhanced detection8 and provide direct evidence of the non-classical nature of the mechanical oscillator without directly measuring its state9. This noninvasive measurement scheme allows to infer information about otherwise inaccessible objects, with potential implications for sensing, open-system dynamics and fundamental tests of quantum gravity. In the future, similar on-chip devices could be used to entangle subsystems on very different energy scales, such as microwave and optical photons. acknowledged_ssus: - _id: NanoFab article_processing_charge: No arxiv: 1 author: - first_name: Shabir full_name: Barzanjeh, Shabir id: 2D25E1F6-F248-11E8-B48F-1D18A9856A87 last_name: Barzanjeh orcid: 0000-0003-0415-1423 - first_name: Elena full_name: Redchenko, Elena id: 2C21D6E8-F248-11E8-B48F-1D18A9856A87 last_name: Redchenko - first_name: Matilda full_name: Peruzzo, Matilda id: 3F920B30-F248-11E8-B48F-1D18A9856A87 last_name: Peruzzo orcid: 0000-0002-3415-4628 - first_name: Matthias full_name: Wulf, Matthias id: 45598606-F248-11E8-B48F-1D18A9856A87 last_name: Wulf orcid: 0000-0001-6613-1378 - first_name: Dylan full_name: Lewis, Dylan last_name: Lewis - first_name: Georg M full_name: Arnold, Georg M id: 3770C838-F248-11E8-B48F-1D18A9856A87 last_name: Arnold orcid: 0000-0003-1397-7876 - first_name: Johannes M full_name: Fink, Johannes M id: 4B591CBA-F248-11E8-B48F-1D18A9856A87 last_name: Fink orcid: 0000-0001-8112-028X citation: ama: Barzanjeh S, Redchenko E, Peruzzo M, et al. Stationary entangled radiation from micromechanical motion. Nature. 2019;570:480-483. doi:10.1038/s41586-019-1320-2 apa: Barzanjeh, S., Redchenko, E., Peruzzo, M., Wulf, M., Lewis, D., Arnold, G. M., & Fink, J. M. (2019). Stationary entangled radiation from micromechanical motion. Nature. Nature Publishing Group. https://doi.org/10.1038/s41586-019-1320-2 chicago: Barzanjeh, Shabir, Elena Redchenko, Matilda Peruzzo, Matthias Wulf, Dylan Lewis, Georg M Arnold, and Johannes M Fink. “Stationary Entangled Radiation from Micromechanical Motion.” Nature. Nature Publishing Group, 2019. https://doi.org/10.1038/s41586-019-1320-2. ieee: S. Barzanjeh et al., “Stationary entangled radiation from micromechanical motion,” Nature, vol. 570. Nature Publishing Group, pp. 480–483, 2019. ista: Barzanjeh S, Redchenko E, Peruzzo M, Wulf M, Lewis D, Arnold GM, Fink JM. 2019. Stationary entangled radiation from micromechanical motion. Nature. 570, 480–483. mla: Barzanjeh, Shabir, et al. “Stationary Entangled Radiation from Micromechanical Motion.” Nature, vol. 570, Nature Publishing Group, 2019, pp. 480–83, doi:10.1038/s41586-019-1320-2. short: S. Barzanjeh, E. Redchenko, M. Peruzzo, M. Wulf, D. Lewis, G.M. Arnold, J.M. Fink, Nature 570 (2019) 480–483. date_created: 2019-07-07T21:59:20Z date_published: 2019-06-27T00:00:00Z date_updated: 2026-05-14T22:31:25Z day: '27' department: - _id: JoFi doi: 10.1038/s41586-019-1320-2 ec_funded: 1 external_id: arxiv: - '1809.05865' isi: - '000472860000042' intvolume: ' 570' isi: 1 language: - iso: eng main_file_link: - open_access: '1' url: https://arxiv.org/abs/1809.05865 month: '06' oa: 1 oa_version: Preprint page: 480-483 project: - _id: 257EB838-B435-11E9-9278-68D0E5697425 call_identifier: H2020 grant_number: '732894' name: Hybrid Optomechanical Technologies - _id: 26336814-B435-11E9-9278-68D0E5697425 call_identifier: H2020 grant_number: '758053' name: A Fiber Optic Transceiver for Superconducting Qubits - _id: 258047B6-B435-11E9-9278-68D0E5697425 call_identifier: H2020 grant_number: '707438' name: 'Microwave-to-Optical Quantum Link: Quantum Teleportation and Quantum Illumination with cavity Optomechanics' - _id: 2671EB66-B435-11E9-9278-68D0E5697425 name: Coherent on-chip conversion of superconducting qubit signals from microwaves to optical frequencies publication: Nature publication_status: published publisher: Nature Publishing Group quality_controlled: '1' related_material: record: - id: '18871' relation: dissertation_contains status: public scopus_import: '1' status: public title: Stationary entangled radiation from micromechanical motion type: journal_article user_id: 4359f0d1-fa6c-11eb-b949-802e58b17ae8 volume: 570 year: '2019' ... --- _id: '11508' abstract: - lang: eng text: Distant luminous Lyman-α emitters (LAEs) are excellent targets for spectroscopic observations of galaxies in the epoch of reionisation (EoR). We present deep high-resolution (R = 5000) VLT/X-shooter observations, along with an extensive collection of photometric data of COLA1, a proposed double peaked LAE at z = 6.6. We rule out the possibility that COLA1’s emission line is an [OII] doublet at z = 1.475 on the basis of i) the asymmetric red line-profile and flux ratio of the peaks (blue/red=0.31 ± 0.03) and ii) an unphysical [OII]/Hα ratio ([OII]/Hα >  22). We show that COLA1’s observed B-band flux is explained by a faint extended foreground LAE, for which we detect Lyα and [OIII] at z = 2.142. We thus conclude that COLA1 is a real double-peaked LAE at z = 6.593, the first discovered at z >  6. COLA1 is UV luminous (M1500 = −21.6 ± 0.3), has a high equivalent width (EW0,Lyα = 120−40+50 Å) and very compact Lyα emission (r50,Lyα = 0.33−0.04+0.07 kpc). Relatively weak inferred Hβ+[OIII] line-emission from Spitzer/IRAC indicates an extremely low metallicity of Z <  1/20 Z⊙ or reduced strength of nebular lines due to high escape of ionising photons. The small Lyα peak separation of 220 ± 20 km s−1 implies a low HI column density and an ionising photon escape fraction of ≈15 − 30%, providing the first direct evidence that such galaxies contribute actively to the reionisation of the Universe at z >  6. Based on simple estimates, we find that COLA1 could have provided just enough photons to reionise its own ≈0.3 pMpc (2.3 cMpc) bubble, allowing the blue Lyα line to be observed. However, we also discuss alternative scenarios explaining the detected double peaked nature of COLA1. Our results show that future high-resolution observations of statistical samples of double peaked LAEs at z >  5 are a promising probe of the occurrence of ionised regions around galaxies in the EoR. acknowledgement: JM acknowledges the award of a Huygens PhD fellowship from Leiden University. MG acknowledges support from NASA grant NNX17AK58G. APA, PhD::SPACE fellow, acknowledges support from the FCT through the fellowship PD/BD/52706/2014. Based on observations made with ESO Telescopes at the La Silla Paranal Observatory under programme IDs 294.A-5018, 098.A-0819, 099.A-0254 and 0100.A-0213. We are grateful for the excellent data-sets from the COSMOS and UltraVISTA survey teams. This research was supported by the Munich Institute for Astro- and Particle Physics (MIAPP) of the DFG cluster of excellence “Origin and Structure of the Universe”. We thank the referee for their comments that improved the paper. We also thank Christoph Behrens, Len Cowie, Koki Kakiichi, Peter Laursen, Charlotte Mason, Eros Vanzella, Lewis Weinberger and Johannes Zabl for discussions. We have benefited from the public available programming language Python, including the numpy, matplotlib, scipy and astropy packages (Hunter 2007; Astropy Collaboration 2013), the astronomical imaging tools Swarp (Bertin 2010) and ds9 and the Topcat analysis tool (Taylor 2013). article_number: A136 article_processing_charge: No article_type: original arxiv: 1 author: - first_name: Jorryt J full_name: Matthee, Jorryt J id: 7439a258-f3c0-11ec-9501-9df22fe06720 last_name: Matthee orcid: 0000-0003-2871-127X - first_name: David full_name: Sobral, David last_name: Sobral - first_name: Max full_name: Gronke, Max last_name: Gronke - first_name: Ana full_name: Paulino-Afonso, Ana last_name: Paulino-Afonso - first_name: Mauro full_name: Stefanon, Mauro last_name: Stefanon - first_name: Huub full_name: Röttgering, Huub last_name: Röttgering citation: ama: 'Matthee JJ, Sobral D, Gronke M, Paulino-Afonso A, Stefanon M, Röttgering H. Confirmation of double peaked Lyα emission at z = 6.593: Witnessing a galaxy directly contributing to the reionisation of the universe. Astronomy & Astrophysics. 2018;619. doi:10.1051/0004-6361/201833528' apa: 'Matthee, J. J., Sobral, D., Gronke, M., Paulino-Afonso, A., Stefanon, M., & Röttgering, H. (2018). Confirmation of double peaked Lyα emission at z = 6.593: Witnessing a galaxy directly contributing to the reionisation of the universe. Astronomy & Astrophysics. EDP Sciences. https://doi.org/10.1051/0004-6361/201833528' chicago: 'Matthee, Jorryt J, David Sobral, Max Gronke, Ana Paulino-Afonso, Mauro Stefanon, and Huub Röttgering. “Confirmation of Double Peaked Lyα Emission at z = 6.593: Witnessing a Galaxy Directly Contributing to the Reionisation of the Universe.” Astronomy & Astrophysics. EDP Sciences, 2018. https://doi.org/10.1051/0004-6361/201833528.' ieee: 'J. J. Matthee, D. Sobral, M. Gronke, A. Paulino-Afonso, M. Stefanon, and H. Röttgering, “Confirmation of double peaked Lyα emission at z = 6.593: Witnessing a galaxy directly contributing to the reionisation of the universe,” Astronomy & Astrophysics, vol. 619. EDP Sciences, 2018.' ista: 'Matthee JJ, Sobral D, Gronke M, Paulino-Afonso A, Stefanon M, Röttgering H. 2018. Confirmation of double peaked Lyα emission at z = 6.593: Witnessing a galaxy directly contributing to the reionisation of the universe. Astronomy & Astrophysics. 619, A136.' mla: 'Matthee, Jorryt J., et al. “Confirmation of Double Peaked Lyα Emission at z = 6.593: Witnessing a Galaxy Directly Contributing to the Reionisation of the Universe.” Astronomy & Astrophysics, vol. 619, A136, EDP Sciences, 2018, doi:10.1051/0004-6361/201833528.' short: J.J. Matthee, D. Sobral, M. Gronke, A. Paulino-Afonso, M. Stefanon, H. Röttgering, Astronomy & Astrophysics 619 (2018). date_created: 2022-07-06T11:14:23Z date_published: 2018-11-19T00:00:00Z date_updated: 2024-10-14T11:31:36Z day: '19' doi: 10.1051/0004-6361/201833528 extern: '1' external_id: arxiv: - '1805.11621' intvolume: ' 619' keyword: - Space and Planetary Science - Astronomy and Astrophysics - 'galaxies: high-redshift / galaxies: formation / dark ages / reionization / first stars / techniques: spectroscopic / intergalactic medium' language: - iso: eng main_file_link: - open_access: '1' url: https://arxiv.org/abs/1805.11621 month: '11' oa: 1 oa_version: Published Version publication: Astronomy & Astrophysics publication_identifier: eissn: - 1432-0746 issn: - 0004-6361 publication_status: published publisher: EDP Sciences quality_controlled: '1' scopus_import: '1' status: public title: 'Confirmation of double peaked Lyα emission at z = 6.593: Witnessing a galaxy directly contributing to the reionisation of the universe' type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 619 year: '2018' ... --- _id: '11549' abstract: - lang: eng text: We investigate the clustering properties of ∼7000 H β + [O III] and [O II] narrowband-selected emitters at z ∼ 0.8–4.7 from the High-z Emission Line Survey. We find clustering lengths, r0, of 1.5–4.0 h−1 Mpc and minimum dark matter halo masses of 1010.7–12.1 M⊙ for our z = 0.8–3.2 H β + [O III] emitters and r0 ∼ 2.0–8.3 h−1 Mpc and halo masses of 1011.5–12.6 M⊙ for our z = 1.5–4.7 [O II] emitters. We find r0 to strongly increase both with increasing line luminosity and redshift. By taking into account the evolution of the characteristic line luminosity, L⋆(z), and using our model predictions of halo mass given r0, we find a strong, redshift-independent increasing trend between L/L⋆(z) and minimum halo mass. The faintest H β + [O III] emitters are found to reside in 109.5 M⊙ haloes and the brightest emitters in 1013.0 M⊙ haloes. For [O II] emitters, the faintest emitters are found in 1010.5 M⊙ haloes and the brightest emitters in 1012.6 M⊙ haloes. A redshift-independent stellar mass dependency is also observed where the halo mass increases from 1011 to 1012.5 M⊙ for stellar masses of 108.5 to 1011.5 M⊙, respectively. We investigate the interdependencies of these trends by repeating our analysis in a Lline−Mstar grid space for our most populated samples (H β + [O III] z = 0.84 and [O II] z = 1.47) and find that the line luminosity dependency is stronger than the stellar mass dependency on halo mass. For L > L⋆ emitters at all epochs, we find a relatively flat trend with halo masses of 1012.5–13 M⊙, which may be due to quenching mechanisms in massive haloes that is consistent with a transitional halo mass predicted by models. acknowledgement: We thank the anonymous referee for their useful comments and suggestions that improved this study. AAK thanks Anahita Alavi and Irene Shivaei for useful discussion in the making of this paper. AAK acknowledges that this work was supported by NASA Headquarters under the NASA Earth and Space Science Fellowship Program – Grant NNX16AO92H. DS acknowledges financial support from the Netherlands Organization for Scientific Research (NWO) through a Veni fellowship and from Lancaster University through an Early Career Internal Grant A100679. PNB is grateful for support from STFC via grant STM001229/1. IRS acknowledges support from STFC (ST/L00075X/1), the ERC Advanced Grant DUSTYGAL (321334), and a Royal Society/Wolfson Merit award. JM acknowledges the support of a Huygens PhD fellowship from Leiden University. BD acknowledges financial support from NASA through the Astrophysics Data Analysis Program (ADAP), grant number NNX12AE20G. article_processing_charge: No article_type: original arxiv: 1 author: - first_name: A A full_name: Khostovan, A A last_name: Khostovan - first_name: D full_name: Sobral, D last_name: Sobral - first_name: B full_name: Mobasher, B last_name: Mobasher - first_name: P N full_name: Best, P N last_name: Best - first_name: I full_name: Smail, I last_name: Smail - first_name: Jorryt J full_name: Matthee, Jorryt J id: 7439a258-f3c0-11ec-9501-9df22fe06720 last_name: Matthee orcid: 0000-0003-2871-127X - first_name: B full_name: Darvish, B last_name: Darvish - first_name: H full_name: Nayyeri, H last_name: Nayyeri - first_name: S full_name: Hemmati, S last_name: Hemmati - first_name: J P full_name: Stott, J P last_name: Stott citation: ama: 'Khostovan AA, Sobral D, Mobasher B, et al. The clustering of H β + [O III] and [O II] emitters since z ∼ 5: Dependencies with line luminosity and stellar mass. Monthly Notices of the Royal Astronomical Society. 2018;478(3):2999-3015. doi:10.1093/mnras/sty925' apa: 'Khostovan, A. A., Sobral, D., Mobasher, B., Best, P. N., Smail, I., Matthee, J. J., … Stott, J. P. (2018). The clustering of H β + [O III] and [O II] emitters since z ∼ 5: Dependencies with line luminosity and stellar mass. Monthly Notices of the Royal Astronomical Society. Oxford University Press. https://doi.org/10.1093/mnras/sty925' chicago: 'Khostovan, A A, D Sobral, B Mobasher, P N Best, I Smail, Jorryt J Matthee, B Darvish, H Nayyeri, S Hemmati, and J P Stott. “The Clustering of H β + [O III] and [O II] Emitters since z ∼ 5: Dependencies with Line Luminosity and Stellar Mass.” Monthly Notices of the Royal Astronomical Society. Oxford University Press, 2018. https://doi.org/10.1093/mnras/sty925.' ieee: 'A. A. Khostovan et al., “The clustering of H β + [O III] and [O II] emitters since z ∼ 5: Dependencies with line luminosity and stellar mass,” Monthly Notices of the Royal Astronomical Society, vol. 478, no. 3. Oxford University Press, pp. 2999–3015, 2018.' ista: 'Khostovan AA, Sobral D, Mobasher B, Best PN, Smail I, Matthee JJ, Darvish B, Nayyeri H, Hemmati S, Stott JP. 2018. The clustering of H β + [O III] and [O II] emitters since z ∼ 5: Dependencies with line luminosity and stellar mass. Monthly Notices of the Royal Astronomical Society. 478(3), 2999–3015.' mla: 'Khostovan, A. A., et al. “The Clustering of H β + [O III] and [O II] Emitters since z ∼ 5: Dependencies with Line Luminosity and Stellar Mass.” Monthly Notices of the Royal Astronomical Society, vol. 478, no. 3, Oxford University Press, 2018, pp. 2999–3015, doi:10.1093/mnras/sty925.' short: A.A. Khostovan, D. Sobral, B. Mobasher, P.N. Best, I. Smail, J.J. Matthee, B. Darvish, H. Nayyeri, S. Hemmati, J.P. Stott, Monthly Notices of the Royal Astronomical Society 478 (2018) 2999–3015. date_created: 2022-07-08T11:48:48Z date_published: 2018-08-01T00:00:00Z date_updated: 2022-08-19T06:53:39Z day: '01' doi: 10.1093/mnras/sty925 extern: '1' external_id: arxiv: - '1705.01101' intvolume: ' 478' issue: '3' keyword: - Space and Planetary Science - Astronomy and Astrophysics - 'galaxies: evolution' - 'galaxies: haloes' - 'galaxies: high-redshift' - 'galaxies: star formation' - 'cosmology: observations' - large-scale structure of Universe language: - iso: eng main_file_link: - url: https://arxiv.org/abs/1705.01101 month: '08' oa_version: Published Version page: 2999-3015 publication: Monthly Notices of the Royal Astronomical Society publication_identifier: eissn: - 1365-2966 issn: - 0035-8711 publication_status: published publisher: Oxford University Press quality_controlled: '1' scopus_import: '1' status: public title: 'The clustering of H β + [O III] and [O II] emitters since z ∼ 5: Dependencies with line luminosity and stellar mass' type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 478 year: '2018' ... --- _id: '11555' abstract: - lang: eng text: We investigate the morphology of the [C II] emission in a sample of ‘normal’ star-forming galaxies at 5 < z < 7.2 in relation to their UV (rest-frame) counterpart. We use new Atacama Large Millimetre/submillimetre Array (ALMA) observations of galaxies at z ∼ 6–7, as well as a careful re-analysis of archival ALMA data. In total 29 galaxies were analysed, 21 of which are detected in [C II]. For several of the latter the [C II] emission breaks into multiple components. Only a fraction of these [C II] components, if any, is associated with the primary UV systems, while the bulk of the [C II] emission is associated either with fainter UV components, or not associated with any UV counterpart at the current limits. By taking into account the presence of all these components, we find that the L[CII]–SFR (star formation rate) relation at early epochs is fully consistent with the local relation, but it has a dispersion of 0.48 ± 0.07 dex, which is about two times larger than observed locally. We also find that the deviation from the local L[CII]–SFR relation has a weak anticorrelation with the EW(Ly α). The morphological analysis also reveals that [C II] emission is generally much more extended than the UV emission. As a consequence, these primordial galaxies are characterized by a [C II] surface brightness generally much lower than expected from the local Σ[CII]−ΣSFR relation. These properties are likely a consequence of a combination of different effects, namely gas metallicity, [C II] emission from obscured star-forming regions, strong variations of the ionization parameter, and circumgalactic gas in accretion or ejected by these primeval galaxies. acknowledgement: "This paper makes use of the following ALMA data:\r\nADS/JAO.ALMA#2012.1.00719.S, ADS/JAO.ALMA#2012.A.00040.S,\r\nADS/JAO.ALMA#2013.A.00433.S, ADS/JAO.ALMA#2011.0.00115.S,\r\nADS/JAO.ALMA#2012.1.00033.S, ADS/JAO.ALMA#2012.1.00523.S,\r\nADS/JAO.ALMA#2013.1.00815.S, ADS/JAO.ALMA#2015.1.00834.S.,\r\nADS/JAO.ALMA#2015.1.01105.S, AND ADS/JAO.ALMA#2016.1.01240.S\r\nwhich can be retrieved from the ALMA data archive:\r\nhttps://almascience.eso.org/ alma-data/archive. ALMA is a partnership of ESO (representing its member states), NSF (USA) and NINS (Japan), together with NRC (Canada) and NSC and ASIAA (Taiwan), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO, and NAOJ. We are grateful to G. Jones to for providing his [C II] flux maps. RM and SC acknowledge support by the Science and Technology Facilities Council (STFC). RM acknowledges ERC Advanced Grant 695671 ‘QUENCH’. AF acknowledges support from the ERC Advanced Grant INTERSTELLAR H2020/740120." article_processing_charge: No article_type: original arxiv: 1 author: - first_name: S full_name: Carniani, S last_name: Carniani - first_name: R full_name: Maiolino, R last_name: Maiolino - first_name: R full_name: Amorin, R last_name: Amorin - first_name: L full_name: Pentericci, L last_name: Pentericci - first_name: A full_name: Pallottini, A last_name: Pallottini - first_name: A full_name: Ferrara, A last_name: Ferrara - first_name: C J full_name: Willott, C J last_name: Willott - first_name: R full_name: Smit, R last_name: Smit - first_name: Jorryt J full_name: Matthee, Jorryt J id: 7439a258-f3c0-11ec-9501-9df22fe06720 last_name: Matthee orcid: 0000-0003-2871-127X - first_name: D full_name: Sobral, D last_name: Sobral - first_name: P full_name: Santini, P last_name: Santini - first_name: M full_name: Castellano, M last_name: Castellano - first_name: S full_name: De Barros, S last_name: De Barros - first_name: A full_name: Fontana, A last_name: Fontana - first_name: A full_name: Grazian, A last_name: Grazian - first_name: L full_name: Guaita, L last_name: Guaita citation: ama: Carniani S, Maiolino R, Amorin R, et al. Kiloparsec-scale gaseous clumps and star formation at z = 5–7. Monthly Notices of the Royal Astronomical Society. 2018;478(1):1170-1184. doi:10.1093/mnras/sty1088 apa: Carniani, S., Maiolino, R., Amorin, R., Pentericci, L., Pallottini, A., Ferrara, A., … Guaita, L. (2018). Kiloparsec-scale gaseous clumps and star formation at z = 5–7. Monthly Notices of the Royal Astronomical Society. Oxford University Press. https://doi.org/10.1093/mnras/sty1088 chicago: Carniani, S, R Maiolino, R Amorin, L Pentericci, A Pallottini, A Ferrara, C J Willott, et al. “Kiloparsec-Scale Gaseous Clumps and Star Formation at z = 5–7.” Monthly Notices of the Royal Astronomical Society. Oxford University Press, 2018. https://doi.org/10.1093/mnras/sty1088. ieee: S. Carniani et al., “Kiloparsec-scale gaseous clumps and star formation at z = 5–7,” Monthly Notices of the Royal Astronomical Society, vol. 478, no. 1. Oxford University Press, pp. 1170–1184, 2018. ista: Carniani S, Maiolino R, Amorin R, Pentericci L, Pallottini A, Ferrara A, Willott CJ, Smit R, Matthee JJ, Sobral D, Santini P, Castellano M, De Barros S, Fontana A, Grazian A, Guaita L. 2018. Kiloparsec-scale gaseous clumps and star formation at z = 5–7. Monthly Notices of the Royal Astronomical Society. 478(1), 1170–1184. mla: Carniani, S., et al. “Kiloparsec-Scale Gaseous Clumps and Star Formation at z = 5–7.” Monthly Notices of the Royal Astronomical Society, vol. 478, no. 1, Oxford University Press, 2018, pp. 1170–84, doi:10.1093/mnras/sty1088. short: S. Carniani, R. Maiolino, R. Amorin, L. Pentericci, A. Pallottini, A. Ferrara, C.J. Willott, R. Smit, J.J. Matthee, D. Sobral, P. Santini, M. Castellano, S. De Barros, A. Fontana, A. Grazian, L. Guaita, Monthly Notices of the Royal Astronomical Society 478 (2018) 1170–1184. date_created: 2022-07-11T08:05:42Z date_published: 2018-07-01T00:00:00Z date_updated: 2022-08-19T06:58:06Z day: '01' doi: 10.1093/mnras/sty1088 extern: '1' external_id: arxiv: - '1712.03985' intvolume: ' 478' issue: '1' keyword: - Space and Planetary Science - Astronomy and Astrophysics - 'galaxies: evolution' - 'galaxies: high-redshift' - 'galaxies: ISM' - 'galaxies: formation' language: - iso: eng main_file_link: - open_access: '1' url: https://arxiv.org/abs/1712.03985 month: '07' oa: 1 oa_version: Preprint page: 1170-1184 publication: Monthly Notices of the Royal Astronomical Society publication_identifier: eissn: - 1365-2966 issn: - 0035-8711 publication_status: published publisher: Oxford University Press quality_controlled: '1' scopus_import: '1' status: public title: Kiloparsec-scale gaseous clumps and star formation at z = 5–7 type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 478 year: '2018' ... --- _id: '11557' abstract: - lang: eng text: Deep narrow-band surveys have revealed a large population of faint Ly α emitters (LAEs) in the distant Universe, but relatively little is known about the most luminous sources (⁠LLyα≳1042.7 erg s−1; LLyα≳L∗Lyα⁠). Here we present the spectroscopic follow-up of 21 luminous LAEs at z ∼ 2–3 found with panoramic narrow-band surveys over five independent extragalactic fields (≈4 × 106 Mpc3 surveyed at z ∼ 2.2 and z ∼ 3.1). We use WHT/ISIS, Keck/DEIMOS, and VLT/X-SHOOTER to study these sources using high ionization UV lines. Luminous LAEs at z ∼ 2–3 have blue UV slopes (⁠β=−2.0+0.3−0.1⁠) and high Ly α escape fractions (⁠50+20−15 per cent) and span five orders of magnitude in UV luminosity (MUV ≈ −19 to −24). Many (70 per cent) show at least one high ionization rest-frame UV line such as C IV, N V, C III], He II or O III], typically blue-shifted by ≈100–200 km s−1 relative to Ly α. Their Ly α profiles reveal a wide variety of shapes, including significant blue-shifted components and widths from 200 to 4000 km s−1. Overall, 60 ± 11  per cent appear to be active galactic nucleus (AGN) dominated, and at LLyα > 1043.3 erg s−1 and/or MUV < −21.5 virtually all LAEs are AGNs with high ionization parameters (log U = 0.6 ± 0.5) and with metallicities of ≈0.5 − 1 Z⊙. Those lacking signatures of AGNs (40 ± 11  per cent) have lower ionization parameters (⁠logU=−3.0+1.6−0.9 and log ξion = 25.4 ± 0.2) and are apparently metal-poor sources likely powered by young, dust-poor ‘maximal’ starbursts. Our results show that luminous LAEs at z ∼ 2–3 are a diverse population and that 2×L∗Lyα and 2×M∗UV mark a sharp transition in the nature of LAEs, from star formation dominated to AGN dominated. acknowledgement: 'We thank the anonymous reviewer for their timely and constructive comments that greatly helped us to improve the manuscript. DS acknowledges financial support from the Netherlands Organization for Scientific research (NWO) through a Veni fellowship and from Lancaster University through an Early Career Internal Grant A100679. JM acknowledges the support of a Huygens PhD fellowship from Leiden University. BD acknowledges financial support from NASA through the Astrophysics Data Analysis Program (ADAP), grant number NNX12AE20G, and the National Science Foundation, grant number 1716907. IRS acknowledges support from the ERC Advanced Grant DUSTYGAL (321334), STFC (ST/P000541/1), and a Royal Society/Wolfson Merit Award. PNB is grateful for support from STFC via grant ST/M001229/1. We thank Anne Verhamme, Kimihiko Nakajima, Ryan Trainor, Sangeeta Malhotra, Max Gronke, James Rhoads, Fang Xia An, Matthew Hayes, Takashi Kojima, Mark Dijkstra, and Anne Jaskot for many helpful and engaging discussions, particularly during the SnowCLAW Ly α workshop. We thank Bruno Ribeiro, Stephane Charlot, and Joseph Caruana for comments on the manuscript. The authors would also like to thank Ingrid Tengs, Meg Singleton, Ali Khostovan, and Sara Perez for participating in part of the observations. We also thank Joao Calhau, Leah Morabito, Sergio Santos, and Aayush Saxena for their assistance with the narrow-band observations which allowed to select some of the sour ces. Based on observations obtained with the William Herschel Telescope, program: W16AN004; the Very Large Telescope, programs: 098.A-0819 & 099.A-0254; and the Keck II telescope, program: C267D. Based on data products from observations made with ESO Telescopes at the La Silla Paranal Observatory under ESO programme IDs 294.A-5018, 294.A-5039, 092.A-0786, 093.A-0561, 097.A-0943, 098.A-0819, 099.A-0254 and 179.A-2005. The authors acknowledge the award of service time (SW2014b20) on the WHT. WHT and its service programme are operated on the island of La Palma by the Isaac Newton Group in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias. The authors would also like to thank all the extremely helpful observatory staff that have greatly contributed towards our observations, particularly Fiona Riddick, Lilian Dominguez, Florencia Jimenez, and Ian Skillen. We have benefited greatly from the publicly available programming language PYTHON, including the NUMPY & SCIPY (Van Der Walt, Colbert & Varoquaux 2011; Jones et al. 2001), MATPLOTLIB (Hunter 2007), ASTROPY (Astropy Collaboration et al. 2013), and the TOPCAT analysis program (Taylor 2013). This research has made use of the VizieR catalogue access tool, CDS, Strasbourg, France.' article_processing_charge: No article_type: original arxiv: 1 author: - first_name: David full_name: Sobral, David last_name: Sobral - first_name: Jorryt J full_name: Matthee, Jorryt J id: 7439a258-f3c0-11ec-9501-9df22fe06720 last_name: Matthee orcid: 0000-0003-2871-127X - first_name: Behnam full_name: Darvish, Behnam last_name: Darvish - first_name: Ian full_name: Smail, Ian last_name: Smail - first_name: Philip N full_name: Best, Philip N last_name: Best - first_name: Lara full_name: Alegre, Lara last_name: Alegre - first_name: Huub full_name: Röttgering, Huub last_name: Röttgering - first_name: Bahram full_name: Mobasher, Bahram last_name: Mobasher - first_name: Ana full_name: Paulino-Afonso, Ana last_name: Paulino-Afonso - first_name: Andra full_name: Stroe, Andra last_name: Stroe - first_name: Iván full_name: Oteo, Iván last_name: Oteo citation: ama: 'Sobral D, Matthee JJ, Darvish B, et al. The nature of luminous Ly α emitters at z ∼ 2–3: Maximal dust-poor starbursts and highly ionizing AGN. Monthly Notices of the Royal Astronomical Society. 2018;477(2):2817-2840. doi:10.1093/mnras/sty782' apa: 'Sobral, D., Matthee, J. J., Darvish, B., Smail, I., Best, P. N., Alegre, L., … Oteo, I. (2018). The nature of luminous Ly α emitters at z ∼ 2–3: Maximal dust-poor starbursts and highly ionizing AGN. Monthly Notices of the Royal Astronomical Society. Oxford University Press. https://doi.org/10.1093/mnras/sty782' chicago: 'Sobral, David, Jorryt J Matthee, Behnam Darvish, Ian Smail, Philip N Best, Lara Alegre, Huub Röttgering, et al. “The Nature of Luminous Ly α Emitters at z ∼ 2–3: Maximal Dust-Poor Starbursts and Highly Ionizing AGN.” Monthly Notices of the Royal Astronomical Society. Oxford University Press, 2018. https://doi.org/10.1093/mnras/sty782.' ieee: 'D. Sobral et al., “The nature of luminous Ly α emitters at z ∼ 2–3: Maximal dust-poor starbursts and highly ionizing AGN,” Monthly Notices of the Royal Astronomical Society, vol. 477, no. 2. Oxford University Press, pp. 2817–2840, 2018.' ista: 'Sobral D, Matthee JJ, Darvish B, Smail I, Best PN, Alegre L, Röttgering H, Mobasher B, Paulino-Afonso A, Stroe A, Oteo I. 2018. The nature of luminous Ly α emitters at z ∼ 2–3: Maximal dust-poor starbursts and highly ionizing AGN. Monthly Notices of the Royal Astronomical Society. 477(2), 2817–2840.' mla: 'Sobral, David, et al. “The Nature of Luminous Ly α Emitters at z ∼ 2–3: Maximal Dust-Poor Starbursts and Highly Ionizing AGN.” Monthly Notices of the Royal Astronomical Society, vol. 477, no. 2, Oxford University Press, 2018, pp. 2817–40, doi:10.1093/mnras/sty782.' short: D. Sobral, J.J. Matthee, B. Darvish, I. Smail, P.N. Best, L. Alegre, H. Röttgering, B. Mobasher, A. Paulino-Afonso, A. Stroe, I. Oteo, Monthly Notices of the Royal Astronomical Society 477 (2018) 2817–2840. date_created: 2022-07-12T07:18:02Z date_published: 2018-06-01T00:00:00Z date_updated: 2022-08-19T07:01:08Z day: '01' doi: 10.1093/mnras/sty782 extern: '1' external_id: arxiv: - '1802.10102' intvolume: ' 477' issue: '2' keyword: - Space and Planetary Science - Astronomy and Astrophysics - 'galaxies: active' - 'galaxies: evolution' - 'galaxies: high-redshift' - 'galaxies: ISM' - 'galaxies: starburst' - 'cosmology: observations' language: - iso: eng main_file_link: - open_access: '1' url: https://arxiv.org/abs/1802.10102 month: '06' oa: 1 oa_version: Preprint page: 2817-2840 publication: Monthly Notices of the Royal Astronomical Society publication_identifier: eissn: - 1365-2966 issn: - 0035-8711 publication_status: published publisher: Oxford University Press quality_controlled: '1' scopus_import: '1' status: public title: 'The nature of luminous Ly α emitters at z ∼ 2–3: Maximal dust-poor starbursts and highly ionizing AGN' type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 477 year: '2018' ... --- _id: '11558' abstract: - lang: eng text: We present and explore deep narrow- and medium-band data obtained with the Subaru and the Isaac Newton Telescopes in the ∼2 deg2 COSMOS field. We use these data as an extremely wide, low-resolution (R ∼ 20–80) Integral Field Unit survey to slice through the COSMOS field and obtain a large sample of ∼4000 Ly α emitters (LAEs) from z ∼ 2 to 6 in 16 redshift slices (SC4K). We present new Ly α luminosity functions (LFs) covering a comoving volume of ∼108 Mpc3. SC4K extensively complements ultradeep surveys, jointly covering over 4 dex in Ly α luminosity and revealing a global (2.5 < z < 6) synergy LF with α=−1.93+0.12−0.12⁠, log10Φ∗Lyα=−3.45+0.22−0.29 Mpc−3, and log10L∗Lyα=42.93+0.15−0.11 erg s−1. The Schechter component of the Ly α LF reveals a factor ∼5 rise in L∗Lyα and a ∼7 × decline in Φ∗Lyα from z ∼ 2 to 6. The data reveal an extra power-law (or Schechter) component above LLy α ≈ 1043.3 erg s−1 at z ∼ 2.2–3.5 and we show that it is partially driven by X-ray and radio active galactic nucleus (AGN), as their Ly α LF resembles the excess. The power-law component vanishes and/or is below our detection limits above z > 3.5, likely linked with the evolution of the AGN population. The Ly α luminosity density rises by a factor ∼2 from z ∼ 2 to 3 but is then found to be roughly constant (⁠1.1+0.2−0.2×1040 erg s−1 Mpc−3) to z ∼ 6, despite the ∼0.7 dex drop in ultraviolet (UV) luminosity density. The Ly α/UV luminosity density ratio rises from 4 ± 1 per cent to 30 ± 6 per cent from z ∼ 2.2 to 6. Our results imply a rise of a factor of ≈2 in the global ionization efficiency (ξion) and a factor ≈4 ± 1 in the Ly α escape fraction from z ∼ 2 to 6, hinting for evolution in both the typical burstiness/stellar populations and even more so in the typical interstellar medium conditions allowing Ly α photons to escape. acknowledgement: "We thank the anonymous referee for their constructive comments that helped us improve the manuscript. DS acknowledges the hospitality of the IAC and a Severo Ochoa visiting grant. SS and JC acknowledge studentships from the Lancaster University. JM acknowledges a Huygens PhD fellowship from Leiden University. APA acknowledges financial support from the Science and Technology Foundation (FCT, Portugal) through research grants UID/FIS/04434/2013 and fellowship PD/BD/52706/2014. The authors thank Alyssa Drake, Kimihiko Nakajima, Yuichi Harikane, Max Gronke, Irene Shivaei, Helmut Dannerbauer, Huub Rottgering, ¨ Marius Eide, and Masami Ouchi for many engaging and stimulating discussions. We also thank Sara Perez, Alex Bennett, and Tom Rose for their involvement in the early stages of this project. Based on data products from observations made with European Southern Observatory (ESO) Telescopes at the La Silla Paranal Observatory under ESO programme IDs 294.A-5018, 097.A 0943,\r\n098.A-0819, 099.A-0254, and 179.A-2005 and on data products produced by TERAPIX and the Cambridge Astronomy Survey Unit on behalf of the UltraVISTA consortium. Based on observations using the WFC on the 2.5 m INT, as part of programmes 2013AN002, 2013BN008, 2014AC88, 2014AN002, 2014BN006, 2014BC118, and 2016AN001. The INT is operated on the island of La Palma by the Isaac Newton Group in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias. This work is based in part on data products produced at TERAPIX available at the Canadian Astronomy Data Centre as part of the Canada–France– Hawaii Telescope Legacy Survey (CFHTLS), a collaborative project of NRC and CNRS.\r\nWe are grateful to the CFHTLS, COSMOS-UltraVISTA, and COSMOS survey teams. We are also unmeasurably thankful to the pioneering and continuous work from previous Ly α surveys’ teams. Without these previous Ly α and the wider reach legacy surveys, this research would have been impossible. We also thank the VUDS team for making available spectroscopic redshifts from data obtained with VIMOS at the European Southern Observatory Very Large Telescope, Paranal, Chile, under Large Programme 185.A-0791. Finally, the authors acknowledge the unique value of the publicly available programming language PYTHON, including the NUMPY and SCIPY (Van Der Walt, Colbert & Varoquaux 2011; Jones et al. 2001), MATPLOTLIB (Hunter 2007), ASTROPY (Astropy Collaboration et al. 2013), and the TOPCAT analysis program (Taylor 2005). We publicly release a catalogue with all LAEs used in this paper (SC4K), so it can be freely explored by the community (see five example entries in Table A1)." article_processing_charge: No article_type: original arxiv: 1 author: - first_name: David full_name: Sobral, David last_name: Sobral - first_name: Sérgio full_name: Santos, Sérgio last_name: Santos - first_name: Jorryt J full_name: Matthee, Jorryt J id: 7439a258-f3c0-11ec-9501-9df22fe06720 last_name: Matthee orcid: 0000-0003-2871-127X - first_name: Ana full_name: Paulino-Afonso, Ana last_name: Paulino-Afonso - first_name: Bruno full_name: Ribeiro, Bruno last_name: Ribeiro - first_name: João full_name: Calhau, João last_name: Calhau - first_name: Ali A full_name: Khostovan, Ali A last_name: Khostovan citation: ama: 'Sobral D, Santos S, Matthee JJ, et al. Slicing COSMOS with SC4K: The evolution of typical Ly α emitters and the Ly α escape fraction from z ∼ 2 to 6. Monthly Notices of the Royal Astronomical Society. 2018;476(4):4725-4752. doi:10.1093/mnras/sty378' apa: 'Sobral, D., Santos, S., Matthee, J. J., Paulino-Afonso, A., Ribeiro, B., Calhau, J., & Khostovan, A. A. (2018). Slicing COSMOS with SC4K: The evolution of typical Ly α emitters and the Ly α escape fraction from z ∼ 2 to 6. Monthly Notices of the Royal Astronomical Society. Oxford University Press. https://doi.org/10.1093/mnras/sty378' chicago: 'Sobral, David, Sérgio Santos, Jorryt J Matthee, Ana Paulino-Afonso, Bruno Ribeiro, João Calhau, and Ali A Khostovan. “Slicing COSMOS with SC4K: The Evolution of Typical Ly α Emitters and the Ly α Escape Fraction from z ∼ 2 to 6.” Monthly Notices of the Royal Astronomical Society. Oxford University Press, 2018. https://doi.org/10.1093/mnras/sty378.' ieee: 'D. Sobral et al., “Slicing COSMOS with SC4K: The evolution of typical Ly α emitters and the Ly α escape fraction from z ∼ 2 to 6,” Monthly Notices of the Royal Astronomical Society, vol. 476, no. 4. Oxford University Press, pp. 4725–4752, 2018.' ista: 'Sobral D, Santos S, Matthee JJ, Paulino-Afonso A, Ribeiro B, Calhau J, Khostovan AA. 2018. Slicing COSMOS with SC4K: The evolution of typical Ly α emitters and the Ly α escape fraction from z ∼ 2 to 6. Monthly Notices of the Royal Astronomical Society. 476(4), 4725–4752.' mla: 'Sobral, David, et al. “Slicing COSMOS with SC4K: The Evolution of Typical Ly α Emitters and the Ly α Escape Fraction from z ∼ 2 to 6.” Monthly Notices of the Royal Astronomical Society, vol. 476, no. 4, Oxford University Press, 2018, pp. 4725–52, doi:10.1093/mnras/sty378.' short: D. Sobral, S. Santos, J.J. Matthee, A. Paulino-Afonso, B. Ribeiro, J. Calhau, A.A. Khostovan, Monthly Notices of the Royal Astronomical Society 476 (2018) 4725–4752. date_created: 2022-07-12T10:41:08Z date_published: 2018-06-01T00:00:00Z date_updated: 2022-08-19T07:04:45Z day: '01' doi: 10.1093/mnras/sty378 extern: '1' external_id: arxiv: - '1712.04451' intvolume: ' 476' issue: '4' keyword: - Space and Planetary Science - Astronomy and Astrophysics - 'galaxies: evolution' - 'galaxies: formation' - 'galaxies: high-redshift' - 'galaxies: luminosity function' - mass function - 'galaxies: statistics' language: - iso: eng main_file_link: - open_access: '1' url: https://arxiv.org/abs/1712.04451 month: '06' oa: 1 oa_version: Preprint page: 4725-4752 publication: Monthly Notices of the Royal Astronomical Society publication_identifier: eissn: - 1365-2966 issn: - 0035-8711 publication_status: published publisher: Oxford University Press quality_controlled: '1' scopus_import: '1' status: public title: 'Slicing COSMOS with SC4K: The evolution of typical Ly α emitters and the Ly α escape fraction from z ∼ 2 to 6' type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 476 year: '2018' ... --- _id: '11584' abstract: - lang: eng text: Observations show that star-forming galaxies reside on a tight 3D plane between mass, gas-phase metallicity, and star formation rate (SFR), which can be explained by the interplay between metal-poor gas inflows, SFR and outflows. However, different metals are released on different time-scales, which may affect the slope of this relation. Here, we use central, star-forming galaxies with Mstar = 109.0–10.5 M⊙ from the EAGLE hydrodynamical simulation to examine 3D relations between mass, SFR, and chemical enrichment using absolute and relative C, N, O, and Fe abundances. We show that the scatter is smaller when gas-phase α-enhancement is used rather than metallicity. A similar plane also exists for stellar α-enhancement, implying that present-day specific SFRs are correlated with long time-scale star formation histories. Between z = 0 and 1, the α-enhancement plane is even more insensitive to redshift than the plane using metallicity. However, it evolves at z > 1 due to lagging iron yields. At fixed mass, galaxies with higher SFRs have star formation histories shifted towards late times, are more α-enhanced, and this α-enhancement increases with redshift as observed. These findings suggest that relations between physical properties inferred from observations may be affected by systematic variations in α-enhancements. acknowledgement: We thank the anonymous referee for their constructive comments. JM acknowledges the support of a Huygens PhD fellowship from Leiden University. We thank Jarle Brinchmann, Rob Crain and David Sobral for discussions. We acknowledge the use of the TOPCAT software (Taylor 2013) for assisting in rapid exploration of multidimensional data sets and the use of PYTHON and its NUMPY, MATPLOTLIB, and PANDAS packages. article_processing_charge: No article_type: original arxiv: 1 author: - first_name: Jorryt J full_name: Matthee, Jorryt J id: 7439a258-f3c0-11ec-9501-9df22fe06720 last_name: Matthee orcid: 0000-0003-2871-127X - first_name: Joop full_name: Schaye, Joop last_name: Schaye citation: ama: 'Matthee JJ, Schaye J. Star-forming galaxies are predicted to lie on a fundamental plane of mass, star formation rate, and α-enhancement. Monthly Notices of the Royal Astronomical Society: Letters. 2018;479(1):L34-L39. doi:10.1093/mnrasl/sly093' apa: 'Matthee, J. J., & Schaye, J. (2018). Star-forming galaxies are predicted to lie on a fundamental plane of mass, star formation rate, and α-enhancement. Monthly Notices of the Royal Astronomical Society: Letters. Oxford University Press. https://doi.org/10.1093/mnrasl/sly093' chicago: 'Matthee, Jorryt J, and Joop Schaye. “Star-Forming Galaxies Are Predicted to Lie on a Fundamental Plane of Mass, Star Formation Rate, and α-Enhancement.” Monthly Notices of the Royal Astronomical Society: Letters. Oxford University Press, 2018. https://doi.org/10.1093/mnrasl/sly093.' ieee: 'J. J. Matthee and J. Schaye, “Star-forming galaxies are predicted to lie on a fundamental plane of mass, star formation rate, and α-enhancement,” Monthly Notices of the Royal Astronomical Society: Letters, vol. 479, no. 1. Oxford University Press, pp. L34–L39, 2018.' ista: 'Matthee JJ, Schaye J. 2018. Star-forming galaxies are predicted to lie on a fundamental plane of mass, star formation rate, and α-enhancement. Monthly Notices of the Royal Astronomical Society: Letters. 479(1), L34–L39.' mla: 'Matthee, Jorryt J., and Joop Schaye. “Star-Forming Galaxies Are Predicted to Lie on a Fundamental Plane of Mass, Star Formation Rate, and α-Enhancement.” Monthly Notices of the Royal Astronomical Society: Letters, vol. 479, no. 1, Oxford University Press, 2018, pp. L34–39, doi:10.1093/mnrasl/sly093.' short: 'J.J. Matthee, J. Schaye, Monthly Notices of the Royal Astronomical Society: Letters 479 (2018) L34–L39.' date_created: 2022-07-14T12:49:47Z date_published: 2018-09-01T00:00:00Z date_updated: 2024-10-14T11:37:53Z day: '01' doi: 10.1093/mnrasl/sly093 extern: '1' external_id: arxiv: - '1802.06786' intvolume: ' 479' issue: '1' keyword: - Space and Planetary Science - Astronomy and Astrophysics - 'galaxies: abundances' - 'galaxies: evolution' - 'galaxies: formation' - 'galaxies: star formation' language: - iso: eng main_file_link: - open_access: '1' url: https://arxiv.org/abs/1802.06786 month: '09' oa: 1 oa_version: Preprint page: L34 - L39 publication: 'Monthly Notices of the Royal Astronomical Society: Letters' publication_identifier: eissn: - 1745-3933 issn: - 1745-3925 publication_status: published publisher: Oxford University Press quality_controlled: '1' scopus_import: '1' status: public title: Star-forming galaxies are predicted to lie on a fundamental plane of mass, star formation rate, and α-enhancement type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 479 year: '2018' ...