@article{18447,
abstract = {We present the first results on the spatial distribution of star formation in 454 star-forming galaxies just after the epoch of reionisation (4.8 < z < 6.5) using Hα emission-line maps and F444W imaging that traces the stellar continuum from the JWST FRESCO NIRCam Slitless Spectroscopy Survey. The Hα equivalent width profiles of star-forming galaxies across the main sequence at z ∼ 5.3 with stellar masses 6.8≤ log(M*/M⊙) < 11.1 increase with radius, which provides direct evidence for the inside-out growth of star-forming galaxies just after the epoch of reionisation. GALFIT was used to calculate half-light radii, Reff, and central surface densities within 1 kiloparsec, Σ1kpc of Hα and the continuum. At a fixed stellar mass of Log(M*/M⊙) = 9.5, Σ1kpc, Hα is 1.04 ± 0.05 times higher than Σ1kpc, C, Reff, Hα is 1.18 ± 0.03 times larger than Reff, C and both Reff measurements are smaller than 1 kiloparsec. These measurements suggest the rapid build-up of compact bulges via star formation just after the epoch of reionisation. By comparison to analogous work done at lower redshifts with Hubble Space Telescope WFC3 slitless spectroscopy as part of the 3D-HST (z ∼ 1) and CLEAR (z ∼ 0.5) surveys, we find that Reff(z) evolves at the same pace for Hα and the continuum, but Σ1kpc(z) evolves faster for Hα than the stellar continuum. As a function of the Hubble parameter, Reff, Hα/Reff,C = 1.1h(z) and Σ1 kpc, Hα/Σ1 kpc,C = h(z)1.3. These parametrisations suggest that the inside-out growth of the disk starts to dominate the inside-out growth of the bulge towards lower redshifts. This is supported by the redshift evolution in the EW(Hα) profiles from FRESCO, 3D-HST, and CLEAR at fixed stellar mass and when star-forming progenitors are traced, in which in EW(Hα) rapidly increases with radius within the half-light radius at z ∼ 5.3, but EW(Hα) increases only significantly with radius in the outer disk at z ∼ 0.5.},
author = {Matharu, Jasleen and Nelson, Erica J. and Brammer, Gabriel and Oesch, Pascal A. and Allen, Natalie and Shivaei, Irene and Naidu, Rohan P. and Chisholm, John and Covelo-Paz, Alba and Fudamoto, Yoshinobu and Giovinazzo, Emma and Herard-Demanche, Thomas and Kerutt, Josephine and Kramarenko, Ivan and Marchesini, Danilo and Meyer, Romain A. and Prieto-Lyon, Gonzalo and Reddy, Naveen and Shuntov, Marko and Weibel, Andrea and Wuyts, Stijn and Xiao, Mengyuan},
issn = {1432-0746},
journal = {Astronomy & Astrophysics},
publisher = {EDP Sciences},
title = {{A first look at spatially resolved star formation at 4.8 < z < 6.5 with JWST FRESCO NIRCam slitless spectroscopy}},
doi = {10.1051/0004-6361/202450522},
volume = {690},
year = {2024},
}
@article{18493,
abstract = {Context. The escape of Lyman-α photons at redshifts greater than two is an ongoing subject of study and an important quantity to further understanding of Lyman-α emitters (LAEs), the transmission of Lyman-α photons through the interstellar medium and intergalactic medium, and the impact these LAEs have on cosmic reionisation.
Aims. This study aims to assess the Lyman-α escape fraction, fesc, Lyα, over the redshift range 2.9 < z < 6.7, focusing on Very Large Telescope/Multi Unit Spectroscopic Explorer (VLT/MUSE) selected, gravitationally lensed, intrinsically faint LAEs. These galaxies are of particular interest as the potential drivers of cosmic reionisation.
Methods. We assessed fesc, Lyα in two ways: through an individual study of 96 LAEs behind the A2744 lensing cluster, with James Webb Space Telescope/Near-Infrared Camera (JWST/NIRCam) and HST data, and through a study of the global evolution of fesc, Lyα using the state-of-the-art luminosity functions for LAEs and the UV-selected ‘parent’ population (dust-corrected). We compared these studies to those in the literature based on brighter samples.
Results. We find a negligible redshift evolution of fesc, Lyα for our individual galaxies; it is likely that it was washed out by significant intrinsic scatter. We observed a more significant evolution towards higher escape fractions with decreasing UV magnitude and fit this relation. When comparing the two luminosity functions to derive fesc, Lyα in a global sense, we saw agreement with previous literature when integrating the luminosity functions to a bright limit. However, when integrating using a faint limit equivalent to the observational limits of our samples, we observed enhanced values of fesc, Lyα, particularly around z ∼ 6, where fesc, Lyα becomes consistent with 100% escape. This indicates for the faint regimes we sampled that galaxies towards reionisation tend to allow very large fractions of Lyman-α photons to escape. We interpret this as evidence of a lack of any significant dust in these populations; our sample is likely dominated by young, highly star-forming chemically unevolved galaxies. Finally, we assessed the contribution of the LAE population to reionisation using our latest values for fesc, Lyα and the LAE luminosity density. The dependence on the escape fraction of Lyman continuum photons is strong, but for values similar to those observed recently in z ∼ 3 LAEs and high-redshift analogues, LAEs could provide all the ionising emissivity necessary for reionisation.},
author = {Goovaerts, I. and Thai, T. T. and Pello, R. and Tuan-Anh, P. and Laporte, N. and Matthee, Jorryt J and Nanayakkara, T. and Pharo, J.},
issn = {1432-0746},
journal = {Astronomy & Astrophysics},
publisher = {EDP Sciences},
title = {{Charting the Lyman-α escape fraction in the range 2.9 < z < 6.7 and consequences for the LAE reionisation contribution}},
doi = {10.1051/0004-6361/202451432},
volume = {690},
year = {2024},
}
@article{18528,
abstract = {The recent measurement of magnetic field strength inside the radiative interior of red giant stars has opened the way toward full 3D characterization of the geometry of stable large-scale magnetic fields. However, current measurements, which are limited to dipolar (ℓ = 1) mixed modes, do not properly constrain the topology of magnetic fields due to degeneracies on the observed magnetic field signature on such ℓ = 1 mode frequencies. Efforts focused toward unambiguous detections of magnetic field configurations are now key to better understand angular momentum transport in stars. We investigated the detectability of complex magnetic field topologies (such as the ones observed at the surface of stars with a radiative envelope with spectropolarimetry) inside the radiative interior of red giants. We focused on a field composed of a combination of a dipole and a quadrupole (quadrudipole) and on an offset field. We explored the potential of probing such magnetic field topologies from a combined measurement of magnetic signatures on ℓ = 1 and quadrupolar (ℓ = 2) mixed mode oscillation frequencies. We first derived the asymptotic theoretical formalism for computing the asymmetric signature in the frequency pattern for ℓ = 2 modes due to a quadrudipole magnetic field. To access asymmetry parameters for more complex magnetic field topologies, we numerically performed a grid search over the parameter space to map the degeneracy of the signatures of given topologies. We demonstrate the crucial role played by ℓ = 2 mixed modes in accessing internal magnetic fields with a quadrupolar component. The degeneracy of the quadrudipole compared to pure dipolar fields is lifted when considering magnetic asymmetries in both ℓ = 1 and ℓ = 2 mode frequencies. In addition to the analytical derivation for the quadrudipole, we present the prospect for complex magnetic field inversions using magnetic sensitivity kernels from standard perturbation analysis for forward modeling. Using this method, we explored the detectability of offset magnetic fields from ℓ = 1 and ℓ = 2 frequencies and demonstrate that offset fields may be mistaken for weak and centered magnetic fields, resulting in underestimating the magnetic field strength in stellar cores. We emphasize the need to characterize ℓ = 2 mixed-mode frequencies, (along with the currently characterized ℓ = 1 mixed modes), to unveil the higher-order components of the geometry of buried magnetic fields and to better constrain angular momentum transport inside stars.},
author = {Das, Srijan B and Einramhof, Lukas and Bugnet, Lisa Annabelle},
issn = {1432-0746},
journal = {Astronomy & Astrophysics},
publisher = {EDP Sciences},
title = {{Unveiling complex magnetic field configurations in red giant stars}},
doi = {10.1051/0004-6361/202450918},
volume = {690},
year = {2024},
}
@article{15336,
abstract = {Submillimeter surveys toward overdense regions in the early Universe are essential for uncovering the obscured star formation and the cold gas content of assembling galaxies within massive dark matter halos. In this work, we present deep ALMA mosaic observations covering an area of ∼2′×2′ around MUSE Quasar Nebula 01 (MQN01), one of the largest and brightest Ly-α emitting nebulae discovered thus far; it surrounds a radio-quiet quasar at z ≃ 3.25. Our observations target the 1.2 and the 3 mm dust continuum as well as the carbon monoxide CO(4–3) transition in galaxies in the vicinity of the quasar. We identify a robust sample of 11 CO-line-emitting galaxies (including a closely separated quasar companion) that lie within ±4000 km s−1 of the quasar systemic redshift. A fraction of these objects were missed in previous deep rest-frame optical/UV surveys, which highlights the critical role of (sub)millimeter imaging. We also detect a total of 11 sources revealed in the dust continuum at 1.2 mm; six of them have either high-fidelity spectroscopic redshift information from rest-frame UV metal absorptions or the CO(4–3) line that places them in the same narrow redshift range. A comparison of the CO luminosity function and 1.2 mm number count density with those of the general fields points to a galaxy overdensity of δ > 10. We find evidence of a systematic flattening at the bright end of the CO luminosity function with respect to the trend measured in blank fields. Our findings reveal that galaxies in dense regions at z ∼ 3 are more massive and significantly richer in molecular gas than galaxies in fields, which enables a faster and accelerated assembly. This is the first in a series of studies aimed at characterizing one of the densest regions of the Universe found so far at z > 3.},
author = {Pensabene, A. and Cantalupo, S. and Cicone, C. and Decarli, R. and Galbiati, M. and Ginolfi, M. and De Beer, S. and Fossati, M. and Fumagalli, M. and Lazeyras, T. and Pezzulli, G. and Travascio, A. and Wang, W. and Matthee, Jorryt J and Maseda, M. V.},
issn = {1432-0746},
journal = {Astronomy & Astrophysics},
publisher = {EDP Sciences},
title = {{ALMA survey of a massive node of the Cosmic Web at z ∼ 3: I. Discovery of a large overdensity of CO emitters}},
doi = {10.1051/0004-6361/202348659},
volume = {684},
year = {2024},
}
@article{18527,
abstract = {Context. Galaxies evolve through a dynamic exchange of material with their immediate surrounding environment, the so-called circumgalactic medium (CGM). Understanding the physics of gas flows and the nature of the CGM is fundamental to studying galaxy evolution, especially at 4 ≤ z ≤ 6 (i.e., after the Epoch of Reionization) when galaxies rapidly assembled their masses and reached their chemical maturity. Galactic outflows are predicted to enrich the CGM with metals, although it has also been suggested that gas stripping in systems undergoing a major merger may play a role.
Aims. In this work, we explore the metal enrichment of the medium around merging galaxies at z ∼ 4.5, observed by the ALMA Large Program to INvestigate [CII] at Early times (ALPINE). To do so, we study the nature of the [CII] 158 μm emission in the CGM around these systems, using simulations to help disentangle the mechanisms contributing to the CGM metal pollution.
Methods. By adopting an updated classification of major merger systems in the ALPINE survey, we selected and analyzed merging galaxies whose components can be spatially and/or spectrally resolved in a robust way. This makes it possible to distinguish between the [CII] emission coming from the single components of the system and that coming from the system as a whole. We also made use of the dustyGadget cosmological simulation to select synthetic analogs of observed galaxies and guide the interpretation of the observational results.
Results. We find a large diffuse [CII] envelope (≳20 kpc) embedding all the merging systems, with at least 25% of the total [CII] emission coming from the medium between the galaxies. Using predictions from dustyGadget, we suggest that this emission has a multi-fold nature, with dynamical interactions between galaxies playing a major role in stripping the gas and enriching the medium with heavy elements.},
author = {Di Cesare, Claudia and Ginolfi, M. and Graziani, L. and Schneider, R. and Romano, M. and Popping, G.},
issn = {1432-0746},
journal = {Astronomy & Astrophysics},
publisher = {EDP Sciences},
title = {{Carbon envelopes around merging galaxies at z ~ 4.5}},
doi = {10.1051/0004-6361/202449164},
volume = {690},
year = {2024},
}
@article{14980,
abstract = {Precision sensing and manipulation of milligram-scale mechanical oscillators has attracted growing interest in the fields of table-top explorations of gravity and tests of quantum mechanics at macroscopic scales. Torsional oscillators present an opportunity in this regard due to their remarked isolation from environmental noise. For torsional motion, an effective employment of optical cavities to enhance optomechanical interactions—as already established for linear oscillators—so far faced certain challenges. Here, we propose a concept for sensing and manipulating torsional motion, where exclusively the torsional rotations of a pendulum are mapped onto the path length of a single two-mirror optical cavity. The concept inherently alleviates many limitations of previous approaches. A proof-of-principle experiment is conducted with a rigidly controlled pendulum to explore the sensing aspects of the concept and to identify practical limitations in a potential state-of-the art setup. Based on this study, we anticipate development of precision torque sensors utilizing torsional pendulums that can support sensitivities below 10−19Nm/√Hz, while the motion of the pendulums are dominated by quantum radiation pressure noise at sub-microwatts of incoming laser power. These developments will provide horizons for experiments at the interface of quantum mechanics and gravity.},
author = {Agafonova, Sofya and Mishra, Umang and Diorico, Fritz R and Hosten, Onur},
issn = {2643-1564},
journal = {Physical Review Research},
number = {1},
publisher = {American Physical Society},
title = {{Zigzag optical cavity for sensing and controlling torsional motion}},
doi = {10.1103/physrevresearch.6.013141},
volume = {6},
year = {2024},
}
@article{14802,
abstract = {Frequency-stable lasers form the back bone of precision measurements in science and technology. Such lasers typically attain their stability through frequency locking to reference cavities. State-of-the-art locking performances to date had been achieved using frequency modulation based methods, complemented with active drift cancellation systems. We demonstrate an all passive, modulation-free laser-cavity locking technique (squash locking) that utilizes changes in spatial beam ellipticity for error signal generation, and a coherent polarization post-selection for noise resilience. By comparing two identically built proof-of-principle systems, we show a frequency locking instability of 5×10−7 relative to the cavity linewidth at 10 s averaging. The results surpass the demonstrated performances of methods engineered over the last five decades, potentially enabling an advancement in the precision control of lasers, while creating avenues for bridging the performance gaps between industrial grade lasers with scientific ones due to the afforded simplicity and scalability.},
author = {Diorico, Fritz R and Zhutov, Artem and Hosten, Onur},
issn = {2334-2536},
journal = {Optica},
keywords = {Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials},
number = {1},
pages = {26--31},
publisher = {Optica Publishing Group},
title = {{Laser-cavity locking utilizing beam ellipticity: accessing the 10−7 instability scale relative to cavity linewidth}},
doi = {10.1364/optica.507451},
volume = {11},
year = {2024},
}
@phdthesis{17225,
abstract = {This thesis describes the development of an atom interferometer designed to exploit the
advantages of utilizing quantum entanglement for enhanced precision measurements beyond
the standard quantum limit. While the project remains ongoing, significant progress has been
made.
A key contribution of this work is the development of Quantrol, an experimental control
system leveraging the ARTIQ framework. This software enables precise timing and control
without requiring prior knowledge of ARTIQ’s implementation details or coding experience.
The interface offers user friendly visual comprehension of the experimental sequence and
extended capabilities, allowing researchers to scan variables with a simple click of a mouse.
The main proposed project is to implement atom interferometric sequence with squeezed input
states inside of a dipole trap generated by a high finesse cavity. The presence of the dipole
trap allows one dimensional atomic cloud split while maintaining relatively strong confinement
in other directions.
We are currently able to trap and cool 87Rb atoms to few micro kelvin temperatures, load
them into the dipole trap and state prepare them to be used for squeezing and interferometric
sequence.},
author = {Li, Vyacheslav},
issn = {2663-337X},
pages = {79},
publisher = {Institute of Science and Technology Austria},
title = {{Towards a quantum entanglement enhanced atom interferomter}},
doi = {10.15479/at:ista:17225},
year = {2024},
}
@article{15169,
abstract = {Interpretation of extracellular recordings can be challenging due to the long range of electric field. This challenge can be mitigated by estimating the current source density (CSD). Here we introduce kCSD-python, an open Python package implementing Kernel Current Source Density (kCSD) method and related tools to facilitate CSD analysis of experimental data and the interpretation of results. We show how to counter the limitations imposed by noise and assumptions in the method itself. kCSD-python allows CSD estimation for an arbitrary distribution of electrodes in 1D, 2D, and 3D, assuming distributions of sources in tissue, a slice, or in a single cell, and includes a range of diagnostic aids. We demonstrate its features in a Jupyter Notebook tutorial which illustrates a typical analytical workflow and main functionalities useful in validating analysis results.},
author = {Chintaluri, Chaitanya and Bejtka, Marta and Sredniawa, Wladyslaw and Czerwinski, Michal and Dzik, Jakub M. and Jedrzejewska-Szmek, Joanna and Wojciki, Daniel K.},
issn = {1553-7358},
journal = {PLoS Computational Biology},
number = {3},
publisher = {Public Library of Science},
title = {{kCSD-python, reliable current source density estimation with quality control}},
doi = {10.1371/journal.pcbi.1011941},
volume = {20},
year = {2024},
}
@inproceedings{17147,
abstract = {Efficient utilization of large-scale biobank data is crucial for inferring the genetic basis of disease and predicting health outcomes from the DNA. Yet we lack efficient, accurate methods that scale to data where electronic health records are linked to whole genome sequence information. To address this issue, our paper develops a new algorithmic paradigm based on Approximate Message Passing (AMP), which is specifically tailored for genomic prediction and association testing. Our method yields comparable out-of-sample prediction accuracy to the state of the art on UK Biobank traits, whilst dramatically improving computational complexity, with a 8x-speed up in the run time. In addition, AMP theory provides a joint association testing framework, which outperforms the currently used REGENIE method, in roughly a third of the compute time. This first, truly large-scale application of the AMP framework lays the foundations for a far wider range of statistical analyses for hundreds of millions of variables measured on millions of people.},
author = {Depope, Al and Mondelli, Marco and Robinson, Matthew Richard},
booktitle = {2024 IEEE International Conference on Acoustics, Speech, and Signal Processing},
isbn = {9798350344851},
issn = {1520-6149},
location = {Seoul, Korea},
pages = {13151--13155},
publisher = {IEEE},
title = {{Inference of genetic effects via approximate message passing}},
doi = {10.1109/ICASSP48485.2024.10447198},
year = {2024},
}
@article{15182,
abstract = {Thermoelectric materials convert heat into electricity, with a broad range of applications near room temperature (RT). However, the library of RT high-performance materials is limited. Traditional high-temperature synthetic methods constrain the range of materials achievable, hindering the ability to surpass crystal structure limitations and engineer defects. Here, a solution-based synthetic approach is introduced, enabling RT synthesis of powders and exploration of densification at lower temperatures to influence the material's microstructure. The approach is exemplified by Ag2Se, an n-type alternative to bismuth telluride. It is demonstrated that the concentration of Ag interstitials, grain boundaries, and dislocations are directly correlated to the sintering temperature, and achieve a figure of merit of 1.1 from RT to 100 °C after optimization. Moreover, insights into and resolve Ag2Se's challenges are provided, including stoichiometry issues leading to irreproducible performances. This work highlights the potential of RT solution synthesis in expanding the repertoire of high-performance thermoelectric materials for practical applications.},
author = {Kleinhanns, Tobias and Milillo, Francesco and Calcabrini, Mariano and Fiedler, Christine and Horta, Sharona and Balazs, Daniel and Strumolo, Marissa J. and Hasler, Roger and Llorca, Jordi and Tkadletz, Michael and Brutchey, Richard L. and Ibáñez, Maria},
issn = {1614-6840},
journal = {Advanced Energy Materials},
number = {22},
publisher = {Wiley},
title = {{A route to high thermoelectric performance: Solution‐based control of microstructure and composition in Ag2Se}},
doi = {10.1002/aenm.202400408},
volume = {14},
year = {2024},
}
@article{18951,
abstract = {We consider local dynamics of the dimer model (perfect matchings) on hypercubic boxes [n]
d . These consist of successively switching the dimers along alternating cycles of prescribed (small) lengths. We study the connectivity properties of the dimer configuration space equipped with these transitions. Answering a question of Freire, Klivans, Milet, and Saldanha, we show that in three dimensions any configuration admits an alternating cycle of length at most 6. We further establish that any configuration on [n] d features order n d−2 alternating cycles of length at most 4d−2. We also prove that the dynamics of dimer configurations on the unit hypercube of dimension d is ergodic when switching alternating cycles of length at most 4d−4. Finally, in the planar but non-bipartite case, we show that parallelogram-shaped boxes in the triangular lattice are ergodic for switching alternating cycles of lengths 4 and 6 only, thus improving a result of Kenyon and Rémila, which also uses 8-cycles. None of our proofs make reference to height functions.},
author = {Hartarsky, Ivailo and Lichev, Lyuben and Toninelli, Fabio Lucio},
issn = {2308-5835},
journal = {Annales de l’Institut Henri Poincaré D, Combinatorics, Physics and their Interactions},
publisher = {EMS Press},
title = {{Local dimer dynamics in higher dimensions}},
doi = {10.4171/aihpd/200},
year = {2024},
}
@inproceedings{18917,
abstract = {An eight-partition of a finite set of points (respectively, of a continuous mass distribution) in ℝ³ consists of three planes that divide the space into 8 octants, such that each open octant contains at most 1/8 of the points (respectively, of the mass). In 1966, Hadwiger showed that any mass distribution in ℝ³ admits an eight-partition; moreover, one can prescribe the normal direction of one of the three planes. The analogous result for finite point sets follows by a standard limit argument.
We prove the following variant of this result: Any mass distribution (or point set) in ℝ³ admits an eight-partition for which the intersection of two of the planes is a line with a prescribed direction.
Moreover, we present an efficient algorithm for calculating an eight-partition of a set of n points in ℝ³ (with prescribed normal direction of one of the planes) in time O^*(n^{5/2}).},
author = {Aronov, Boris and Basit, Abdul and Ramesh, Indu and Tasinato, Gianluca and Wagner, Uli},
booktitle = {40th International Symposium on Computational Geometry},
isbn = {9783959773164},
location = {Athens, Greece},
pages = {8:1--8:15},
publisher = {Schloss Dagstuhl - Leibniz-Zentrum für Informatik},
title = {{Eight-partitioning points in 3D, and efficiently too}},
doi = {10.4230/LIPIcs.SoCG.2024.8},
volume = {293},
year = {2024},
}
@inproceedings{18557,
abstract = {Broadcast and Consensus are most fundamental tasks in distributed computing. These tasks are particularly challenging in dynamic networks where communication across the network links may be unreliable, e.g., due to mobility or failures. Over the last years, researchers have derived several impossibility results and high time complexity lower bounds for these tasks. Specifically for the setting where in each round of communication the adversary is allowed to choose one rooted tree along which the information is disseminated, there is a lower as well as an upper bound that is linear in the number n of nodes for Broadcast and for n ≥ 3 the adversary can guarantee that Consensus never happens. This setting is called the oblivious message adversary for rooted trees. Also note that if the adversary is allowed to choose a graph that does not contain a rooted tree, then it can guarantee that Broadcast and Consensus will never happen. However, such deterministic adversarial models may be overly pessimistic, as many processes in real-world settings are stochastic in nature rather than worst-case. This paper studies Broadcast on stochastic dynamic networks and shows that the situation is very different to the deterministic case. In particular, we show that if information dissemination occurs along random rooted trees and directed Erdős–Rényi graphs, Broadcast completes in O(log n) rounds of communication with high probability. The fundamental insight in our analysis is that key variables are mutually independent. We then study two adversarial models, (a) one with Byzantine nodes and (b) one where an adversary controls the edges. (a) Our techniques without Byzantine nodes are general enough so that they can be extended to Byzantine nodes. (b) In the spirit of smoothed analysis, we introduce the notion of randomized oblivious message adversary, where in each round, an adversary picks k ≤ 2n/3 edges to appear in the communication network, and then a graph (e.g. rooted tree or directed Erdős–Rényi graph) is chosen uniformly at random among the set of all such graphs that include these edges. We show that Broadcast completes in a finite number of rounds, which is, e.g., O(k+log n) rounds in rooted trees. We then extend these results to All-to-All Broadcast, and Consensus, and give lower bounds that show that most of our upper bounds are tight.},
author = {El-Hayek, Antoine and Henzinger, Monika H and Schmid, Stefan},
booktitle = {38th International Symposium on Distributed Computing},
isbn = {9783959773522},
issn = {1868-8969},
location = {Madrid, Spain},
publisher = {Schloss Dagstuhl - Leibniz-Zentrum für Informatik},
title = {{Broadcast and Consensus in stochastic dynamic networks with Byzantine nodes and adversarial edges}},
doi = {10.4230/LIPIcs.DISC.2024.21},
volume = {319},
year = {2024},
}
@inproceedings{17146,
abstract = {The Upper Bound Theorem for convex polytopes implies that the p-th Betti number of the Čech complex of any set of N points in ℝ^d and any radius satisfies β_p = O(N^m), with m = min{p+1, ⌈d/2⌉}. We construct sets in even and odd dimensions, which prove that this upper bound is asymptotically tight. For example, we describe a set of N = 2(n+1) points in ℝ³ and two radii such that the first Betti number of the Čech complex at one radius is (n+1)² - 1, and the second Betti number of the Čech complex at the other radius is n². In particular, there is an arrangement of n contruent balls in ℝ³ that enclose a quadratic number of voids, which answers a long-standing open question in computational geometry.},
author = {Edelsbrunner, Herbert and Pach, János},
booktitle = {40th International Symposium on Computational Geometry},
isbn = {9783959773164},
issn = {1868-8969},
location = {Athens, Greece},
publisher = {Schloss Dagstuhl - Leibniz-Zentrum für Informatik},
title = {{Maximum Betti numbers of Čech complexes}},
doi = {10.4230/LIPIcs.SoCG.2024.53},
volume = {293},
year = {2024},
}
@inproceedings{17426,
abstract = {The robustness of neural networks against input perturbations with bounded
magnitude represents a serious concern in the deployment of deep learning
models in safety-critical systems. Recently, the scientific community has
focused on enhancing certifiable robustness guarantees by crafting 1-Lipschitz
neural networks that leverage Lipschitz bounded dense and convolutional layers.
Although different methods have been proposed in the literature to achieve this
goal, understanding the performance of such methods is not straightforward,
since different metrics can be relevant (e.g., training time, memory usage,
accuracy, certifiable robustness) for different applications. For this reason,
this work provides a thorough theoretical and empirical comparison between
methods by evaluating them in terms of memory usage, speed, and certifiable
robust accuracy. The paper also provides some guidelines and recommendations to
support the user in selecting the methods that work best depending on the
available resources. We provide code at
https://github.com/berndprach/1LipschitzLayersCompared.},
author = {Prach, Bernd and Brau, Fabio and Buttazzo, Giorgio and Lampert, Christoph},
booktitle = {Proceedings of the IEEE/CVF Conference on Computer Vision and Pattern Recognition},
location = {Seattle, WA, United States},
pages = {24574--24583},
publisher = {Computer Vision Foundation},
title = {{1-Lipschitz layers compared: Memory, speed, and certifiable robustness}},
doi = {10.1109/CVPR52733.2024.02320},
year = {2024},
}
@unpublished{18874,
abstract = {Despite extensive research since the community learned about adversarial
examples 10 years ago, we still do not know how to train high-accuracy
classifiers that are guaranteed to be robust to small perturbations of their
inputs. Previous works often argued that this might be because no classifier
exists that is robust and accurate at the same time. However, in computer
vision this assumption does not match reality where humans are usually accurate
and robust on most tasks of interest. We offer an alternative explanation and
show that in certain settings robust generalization is only possible with
unrealistically large amounts of data. More precisely we find a setting where a
robust classifier exists, it is easy to learn an accurate classifier, yet it
requires an exponential amount of data to learn a robust classifier. Based on
this theoretical result, we explore how well robust classifiers generalize on
datasets such as CIFAR-10. We come to the conclusion that on this datasets, the
limitation of current robust models also lies in the generalization, and that
they require a lot of data to do well on the test set. We also show that the
problem is not in the expressiveness or generalization capabilities of current
architectures, and that there are low magnitude features in the data which are
useful for non-robust generalization but are not available for robust
classifiers.},
author = {Prach, Bernd and Lampert, Christoph},
booktitle = {arXiv},
title = {{Intriguing properties of robust classification}},
doi = {10.48550/arXiv.2412.04245},
year = {2024},
}
@inproceedings{17634,
abstract = {System behaviors are traditionally evaluated through binary classifications of correctness, which do not suffice for properties involving quantitative aspects of systems and executions. Quantitative automata offer a more nuanced approach, mapping each execution to a real number by incorporating weighted transitions and value functions generalizing acceptance conditions. In this paper, we introduce QuAK, the first tool designed to automate the analysis of quantitative automata. QuAK currently supports a variety of quantitative automaton types, including Inf, Sup, LimInf, LimSup, LimInfAvg, and LimSupAvg automata, and implements decision procedures for problems such as emptiness, universality, inclusion, equivalence, as well as for checking whether an automaton is safe, live, or constant. Additionally, QuAK is able to compute extremal values when possible, construct safety-liveness decompositions, and monitor system behaviors. We demonstrate the effectiveness of QuAK through experiments focusing on the inclusion, constant-function check, and monitoring problems.},
author = {Chalupa, Marek and Henzinger, Thomas A and Mazzocchi, Nicolas Adrien and Sarac, Naci E},
booktitle = {12th International Symposium on Leveraging Applications of Formal Methods, Verification and Validation},
isbn = {9783031753862},
issn = {1611-3349},
location = {Crete, Greece},
pages = {3--20},
publisher = {Springer Nature},
title = {{QuAK: Quantitative Automata Kit}},
doi = {10.1007/978-3-031-75387-9_1},
volume = {15222},
year = {2024},
}
@inproceedings{18121,
abstract = {It is known that sparsity can improve interpretability for deep neural networks. However, existing methods in the area either require networks that are pre-trained with sparsity constraints, or impose sparsity after the fact, altering the network’s general behavior. In this paper, we demonstrate, for the first time, that sparsity can instead be incorporated into the interpretation process itself, as a sample-specific preprocessing step. Unlike previous work, this approach, which we call SPADE, does not place constraints on the trained model and does not affect its behavior during inference on the sample. Given a trained model and a target sample, SPADE uses sample-targeted pruning to provide a "trace" of the network’s execution on the sample, reducing the network to the most important connections prior to computing an interpretation. We demonstrate that preprocessing with SPADE significantly increases the accuracy of image saliency maps across several interpretability methods. Additionally, SPADE improves the usefulness of neuron visualizations, aiding humans in reasoning about network behavior. Our code is available at https://github.com/IST-DASLab/SPADE.},
author = {Moakhar, Arshia Soltani and Iofinova, Eugenia B and Frantar, Elias and Alistarh, Dan-Adrian},
booktitle = {Proceedings of the 41st International Conference on Machine Learning},
issn = {2640-3498},
location = {Vienna, Austria},
pages = {45955--45987},
publisher = {ML Research Press},
title = {{SPADE: Sparsity-guided debugging for deep neural networks}},
volume = {235},
year = {2024},
}
@article{15297,
abstract = {Populations evolve by accumulating advantageous mutations. Every population has some spatial structure that can be modeled by an underlying network. The network then influences the probability that new advantageous mutations fixate. Amplifiers of selection are networks that increase the fixation probability of advantageous mutants, as compared to the unstructured fully-connected network. Whether or not a network is an amplifier depends on the choice of the random process that governs the evolutionary dynamics. Two popular choices are Moran process with Birth-death updating and Moran process with death-Birth updating. Interestingly, while some networks are amplifiers under Birth-death updating and other networks are amplifiers under death-Birth updating, so far no spatial structures have been found that function as an amplifier under both types of updating simultaneously. In this work, we identify networks that act as amplifiers of selection under both versions of the Moran process. The amplifiers are robust, modular, and increase fixation probability for any mutant fitness advantage in a range r ∈ (1, 1.2). To complement this positive result, we also prove that for certain quantities closely related to fixation probability, it is impossible to improve them simultaneously for both versions of the Moran process. Together, our results highlight how the two versions of the Moran process differ and what they have in common.},
author = {Svoboda, Jakub and Joshi, Soham Shrikant and Tkadlec, Josef and Chatterjee, Krishnendu},
issn = {1553-7358},
journal = {PLoS Computational Biology},
number = {3},
publisher = {Public Library of Science},
title = {{Amplifiers of selection for the Moran process with both Birth-death and death-Birth updating}},
doi = {10.1371/journal.pcbi.1012008},
volume = {20},
year = {2024},
}