@inproceedings{18600, abstract = {The analysis of formal models that include quantitative aspects such as timing or probabilistic choices is performed by quantitative verification tools. Broad and mature tool support is available for computing basic properties such as expected rewards on basic models such as Markov chains. Previous editions of QComp, the comparison of tools for the analysis of quantitative formal models, focused on this setting. Many application scenarios, however, require more advanced property types such as LTL and parameter synthesis queries as well as advanced models like stochastic games and partially observable MDPs. For these, tool support is in its infancy today. This paper presents the outcomes of QComp 2023: a survey of the state of the art in quantitative verification tool support for advanced property types and models. With tools ranging from first research prototypes to well-supported integrations into established toolsets, this report highlights today’s active areas and tomorrow’s challenges in tool-focused research for quantitative verification.}, author = {Andriushchenko, Roman and Bork, Alexander and Budde, Carlos E. and Češka, Milan and Grover, Kush and Hahn, Ernst Moritz and Hartmanns, Arnd and Israelsen, Bryant and Jansen, Nils and Jeppson, Joshua and Junges, Sebastian and Köhl, Maximilian A. and Könighofer, Bettina and Kretinsky, Jan and Meggendorfer, Tobias and Parker, David and Pranger, Stefan and Quatmann, Tim and Ruijters, Enno and Taylor, Landon and Volk, Matthias and Weininger, Maximilian and Zhang, Zhen}, booktitle = {TOOLympics Challenge 2023}, isbn = {9783031676949}, issn = {1611-3349}, pages = {90--146}, publisher = {Springer Nature}, title = {{Tools at the Frontiers of Quantitative Verification: QComp 2023 Competition Report}}, doi = {10.1007/978-3-031-67695-6_4}, volume = {14550}, year = {2024}, } @article{18602, abstract = {Semiconductor quantum dots (QDs) in planar germanium (Ge) heterostructures have emerged as front-runners for future hole-based quantum processors. Here, we present strong coupling between a hole charge qubit, defined in a double quantum dot (DQD) in planar Ge, and microwave photons in a high-impedance (Zr = 1.3 kΩ) resonator based on an array of superconducting quantum interference devices (SQUIDs). Our investigation reveals vacuum-Rabi splittings with coupling strengths up to g0/2π = 260 MHz, and a cooperativity of C ~ 100, dependent on DQD tuning. Furthermore, utilizing the frequency tunability of our resonator, we explore the quenched energy splitting associated with strong Coulomb correlation effects in Ge QDs. The observed enhanced coherence of the strongly correlated excited state signals the presence of distinct symmetries within related spin functions, serving as a precursor to the strong coupling between photons and spin-charge hybrid qubits in planar Ge. This work paves the way towards coherent quantum connections between remote hole qubits in planar Ge, required to scale up hole-based quantum processors.}, author = {De Palma, Franco and Oppliger, Fabian and Jang, Wonjin and Bosco, Stefano and Janik, Marian and Calcaterra, Stefano and Katsaros, Georgios and Isella, Giovanni and Loss, Daniel and Scarlino, Pasquale}, issn = {2041-1723}, journal = {Nature Communications}, publisher = {Springer Nature}, title = {{Strong hole-photon coupling in planar Ge for probing charge degree and strongly correlated states}}, doi = {10.1038/s41467-024-54520-7}, volume = {15}, year = {2024}, } @article{18604, abstract = {A face in a curve arrangement is called popular if it is bounded by the same curve multiple times. Motivated by the automatic generation of curved nonogram puzzles, we investigate possibilities to eliminate the popular faces in an arrangement by inserting a single additional curve. This turns out to be NP-hard; however, it becomes tractable when the number of popular faces is small: We present a randomized FPT-time algorithm where the parameter is the number of popular faces.}, author = {De Nooijer, Phoebe and Terziadis, Soeren and Weinberger, Alexandra and Masárová, Zuzana and Mchedlidze, Tamara and Löffler, Maarten and Rote, Günter}, issn = {1526-1719}, journal = {Journal of Graph Algorithms and Applications}, number = {2}, pages = {47--82}, publisher = {Brown University}, title = {{Removing popular faces in curve arrangements}}, doi = {10.7155/jgaa.v28i2.2988}, volume = {28}, year = {2024}, } @article{18616, abstract = {By patterning an ultrathin layered structure with tiny wells, physicists have created and imaged peculiar states known as quantum scars — revealing behaviour that could be used to boost the performance of electronic devices.}, author = {Abanin, Dmitry and Serbyn, Maksym}, issn = {1476-4687}, journal = {Nature}, number = {8040}, pages = {825--826}, publisher = {Springer Nature}, title = {{Quantum scars make their mark in graphene}}, doi = {10.1038/d41586-024-03649-y}, volume = {635}, year = {2024}, } @article{18617, abstract = {Any complex-valued polynomial on (Rn)k decomposes into an algebraic combination of O(n)-invariant polynomials and harmonic polynomials. This decomposition, separation of variables, is granted to be unique if n≥2k−1. We prove that the condition n≥2k−1 is not only sufficient, but also necessary for uniqueness of the separation. Moreover, we describe the structure of non-uniqueness of the separation in the boundary cases when n=2k−2 and n=2k−3. Formally, we study the kernel of a multiplication map ϕ carrying out separation of variables. We devise a general algorithmic procedure for describing Ker ϕ in the restricted non-stable range k≤n<2k−1. In the full non-stable range n<2k−1, we give formulas for highest weights of generators of the kernel as well as formulas for its Hilbert series. Using the developed methods, we obtain a list of highest weight vectors generating Ker ϕ.}, author = {Beďatš, Daniel}, issn = {0021-8693}, journal = {Journal of Algebra}, pages = {281--304}, publisher = {Elsevier}, title = {{Separation of variables for scalar-valued polynomials in the non-stable range}}, doi = {10.1016/j.jalgebra.2024.04.013}, volume = {651}, year = {2024}, } @article{18627, abstract = {In contrast with extended Bloch waves, a single particle can become spatially localized due to the so-called skin effect originating from non-Hermitian pumping. Here we show that in kinetically constrained many-body systems, the skin effect can instead manifest as dynamical amplification within the Fock space, beyond the intuitively expected and previously studied particle localization and clustering. We exemplify this non-Hermitian Fock skin effect in an asymmetric version of the PXP model and show that it gives rise to ergodicity-breaking eigenstates—the non-Hermitian analogs of quantum many-body scars. A distinguishing feature of these non-Hermitian scars is their enhanced robustness against external disorders. We propose an experimental realization of the non-Hermitian scar enhancement in a tilted Bose-Hubbard optical lattice with laser-induced loss. Additionally, we implement digital simulations of such scar enhancement on the IBM quantum processor. Our results show that the Fock skin effect provides a powerful tool for creating robust nonergodic states in generic open quantum systems.}, author = {Shen, Ruizhe and Qin, Fang and Desaules, Jean-Yves Marc and Papić, Zlatko and Lee, Ching Hua}, issn = {1079-7114}, journal = {Physical Review Letters}, number = {21}, publisher = {American Physical Society}, title = {{Enhanced many-body quantum scars from the non-hermitian fock skin effect}}, doi = {10.1103/PhysRevLett.133.216601}, volume = {133}, year = {2024}, } @article{18628, abstract = {Arctic tidewater glaciers are retreating, serving as key indicators of global warming. This study aims to assess how subglacial hydrology affects glacier front retreat by comparing two glacier–fjord models of the Hansbreen glacier: one incorporating a detailed subglacial hydrology model and another simplifying the subglacial discharge to a single channel centered in the flow line. We first validate the subglacial hydrology model by comparing its discharge channels with observations of plume activity. Simulations conducted from April to December 2010 revealed that the glacier front position aligns more closely with the observations in the coupled model than in the simplified version. Furthermore, the mass loss due to calving and submarine melting is greater in the coupled model, with the calving mass loss reaching 6 Mt by the end of the simulation compared to 4 Mt in the simplified model. These findings highlight the critical role of subglacial hydrology in predicting glacier dynamics and emphasize the importance of detailed modeling in understanding the responses of Arctic tidewater glaciers to climate change.}, author = {De Andrés, Eva and Muñoz Hermosilla, José M and Shahateet, Kaian and Otero, Jaime}, issn = {2306-5338}, journal = {Hydrology}, number = {11}, publisher = {MDPI}, title = {{The importance of solving Subglaciar hydrology in modeling glacier retreat: A case study of Hansbreen, Svalbard}}, doi = {10.3390/hydrology11110193}, volume = {11}, year = {2024}, } @article{18629, abstract = {We study a three-dimensional Gross-Pitaevskii equation that describes a static impurity in a dipolar Bose-Einstein condensate. Our focus is on the interplay between the shape of the impurity and the anisotropy of the medium manifested in the energy and the density of the system. Without external confinement, properties of the system are derived with basic analytical approaches. For a system in a harmonic trap, the model is investigated numerically, using the split-step Crank-Nicolson method. Our results demonstrate that the impurity self-energy is minimized when its shape more closely aligns with the anisotropic character of the bath; in particular a prolate deformed impurity aligned with the direction of the dipoles has the smallest self-energy for a repulsive impurity. Our work complements studies of impurities in Bose gases with zero-range interactions and paves the way for studies of dipolar polarons with a Gross-Pitaevskii equation.}, author = {Shukla, Neelam and Volosniev, Artem and Armstrong, Jeremy R.}, issn = {2469-9934}, journal = {Physical Review A}, number = {5}, publisher = {American Physical Society}, title = {{Anisotropic potential immersed in a dipolar Bose-Einstein condensate}}, doi = {10.1103/PhysRevA.110.053317}, volume = {110}, year = {2024}, } @article{18630, abstract = {Markov chains are the de facto finite-state model for stochastic dynamical systems, and Markov decision processes (MDPs) extend Markov chains by incorporating non-deterministic behaviors. Given an MDP and rewards on states, a classical optimization criterion is the maximal expected total reward where the MDP stops after T steps, which can be computed by a simple dynamic programming algorithm. We consider a natural generalization of the problem where the stopping times can be chosen according to a probability distribution, such that the expected stopping time is T, to optimize the expected total reward. Quite surprisingly we establish inter-reducibility of the expected stopping-time problem for Markov chains with the Positivity problem (which is related to the well-known Skolem problem), for which establishing either decidability or undecidability would be a major breakthrough. Given the hardness of the exact problem, we consider the approximate version of the problem: we show that it can be solved in exponential time for Markov chains and in exponential space for MDPs.}, author = {Chatterjee, Krishnendu and Doyen, Laurent}, issn = {1860-5974}, journal = {Logical Methods in Computer Science}, number = {4}, pages = {11:1--11:34}, publisher = {EPI Sciences}, title = {{Stochastic processes with expected stopping time}}, doi = {10.46298/lmcs-20(4:11)2024}, volume = {20}, year = {2024}, } @article{18651, abstract = {Embryo axis formation begins with the localized expression of biochemical signals, which organize cell movements and determine cell fate. A quail study finds that tissue contraction and resulting long-range changes in tissue tension restrict the area where these biochemical signals are expressed.}, author = {Hino, Naoya and Santos Fernandes Lasbarrères Camelo, Carolina and Heisenberg, Carl-Philipp J}, issn = {1879-0445}, journal = {Current Biology}, number = {24}, pages = {R1230--R1232}, publisher = {Elsevier}, title = {{Development: Turing mechanics}}, doi = {10.1016/j.cub.2024.10.065}, volume = {34}, year = {2024}, } @article{18652, abstract = {Over the last 70 years, information theory and coding has enabled communication technologies that have had an astounding impact on our lives. This is possible due to the match between encoding/decoding strategies and corresponding channel models. Traditional studies of channels have taken one of two extremes: Shannon-theoretic models are inherently average-case in which channel noise is governed by a memoryless stochastic process, whereas coding-theoretic (referred to as “Hamming”) models take a worst-case, adversarial, view of the noise. However, for several existing and emerging communication systems the Shannon/average-case view may be too optimistic, whereas the Hamming/worstcase view may be too pessimistic. This monograph takes up the challenge of studying adversarial channel models that lie between the Shannon and Hamming extremes.}, author = {Dey, Bikash Kumar and Jaggi, Sidharth and Langberg, Michael and Sarwate, Anand D. and Zhang, Yihan}, issn = {1567-2328}, journal = {Foundations and Trends in Communications and Information Theory}, number = {3-4}, pages = {300--588}, publisher = {Now Publishers}, title = {{Codes for adversaries: Between worst-case and average-case jamming}}, doi = {10.1561/0100000112}, volume = {21}, year = {2024}, } @article{18653, abstract = {Charge sensing is a sensitive technique for probing quantum devices, of particular importance for spin-qubit readout. To achieve good readout sensitivities, the proximity of the charge sensor to the device to be measured is a necessity. However, this proximity also means that the operation of the device affects, in turn, the sensor tuning and ultimately the readout sensitivity. We present an approach for compensating for this crosstalk effect allowing for the gate voltages of the measured device to be swept in a 1-V × 1-V window while maintaining a sensor configuration chosen by a Bayesian optimizer. Our algorithm will hopefully be a major contribution to the suite of fully automated solutions required for the operation of large quantum device architectures.}, author = {Hickie, Joseph and Van Straaten, Barnaby and Fedele, Federico and Jirovec, Daniel and Ballabio, Andrea and Chrastina, Daniel and Isella, Giovanni and Katsaros, Georgios and Ares, Natalia}, issn = {2331-7019}, journal = {Physical Review Applied}, number = {6}, publisher = {American Physical Society}, title = {{Automated long-range compensation of an rf quantum dot sensor}}, doi = {10.1103/PhysRevApplied.22.064026}, volume = {22}, year = {2024}, } @article{18654, abstract = {We compute the rotational anisotropy of the free energy of 𝛼−RuCl3 in an external magnetic field. This quantity, known as the magnetotropic susceptibility, 𝑘, relates to the second derivative of the free energy with respect to the angle of rotation. We have used approximation-free, auxiliary-field quantum Monte Carlo simulations for a realistic model of 𝛼−RuCl3 and optimized the path integral to alleviate the negative sign problem. This allows us to reach temperatures down to 30K—an energy scale below the dominant Kitaev coupling. We demonstrate that the magnetotropic spin susceptibility in this model of 𝛼−RuCl3 displays scaling behavior 𝑘=𝑇⁢𝑓⁡(𝐵/𝑇) at high temperatures. Once the uniform susceptibility departs from the Curie law (i.e., at the energy scale of the exchange interactions), it appears to transition to an emergent scalinglike behavior, characterized by a different function 𝑓 at lower temperatures, stemming from the locality of torque fluctuations. We observe a remarkable numerical match between experiment and simulations and we also find qualitative agreement with the pure Kitaev model. In comparison, for the XXZ Heisenberg Hamiltonian, the scaling 𝑘=𝑇⁢𝑓⁡(𝐵/𝑇) breaks down at a temperature scale where the uniform spin susceptibility deviates from the Curie law and never reemerges at low temperatures.}, author = {Sato, Toshihiro and Ramshaw, B. J. and Modic, Kimberly A and Assaad, Fakher F.}, issn = {2469-9969}, journal = {Physical Review B}, number = {20}, publisher = {American Physical Society}, title = {{Scale-invariant magnetic anisotropy in α-RuCl3: A quantum Monte Carlo study}}, doi = {10.1103/PhysRevB.110.L201114}, volume = {110}, year = {2024}, } @article{18655, abstract = {Let Qd be the d-dimensional binary hypercube. We say that P={v1,…,vk} is an increasing path of length k−1 in Qd, if for every i∈[k−1] the edge vivi+1 is obtained by switching some zero coordinate in vi to a one coordinate in vi+1. Form a random subgraph Qdp by retaining each edge in E(Qd) independently with probability p. We show that there is a phase transition with respect to the length of a longest increasing path around p=ed. Let α be a constant and let p=αd. When αe, whp there is a path of length d−2 in Qdp, and in fact, whether it is of length d−2,d−1, or d depends on whether the all-zero and all-one vertices percolate or not.}, author = {Anastos, Michael and Diskin, Sahar and Elboim, Dor and Krivelevich, Michael}, issn = {1083-589X}, journal = {Electronic Communications in Probability}, publisher = {Duke University Press}, title = {{Climbing up a random subgraph of the hypercube}}, doi = {10.1214/24-ECP639}, volume = {29}, year = {2024}, } @inproceedings{18702, abstract = {In this work we prove lower bounds on the (communication) cost of maintaining a shared key among a dynamic group of users. Being “dynamic” means one can add and remove users from the group. This captures important protocols like multicast encryption (ME) and continuous group-key agreement (CGKA), which is the primitive underlying many group messaging applications. We prove our bounds in a combinatorial setting where the state of the protocol progresses in rounds. The state of the protocol in each round is captured by a set system, with each of its elements specifying a set of users who share a secret key. We show this combinatorial model implies bounds in symbolic models for ME and CGKA that capture, as building blocks, PRGs, PRFs, dual PRFs, secret sharing, and symmetric encryption in the setting of ME, and PRGs, PRFs, dual PRFs, secret sharing, public-key encryption, and key-updatable public-key encryption in the setting of CGKA. The models are related to the ones used by Micciancio and Panjwani (Eurocrypt’04) and Bienstock et al. (TCC’20) to analyze ME and CGKA, respectively. We prove – using the Bollobás’ Set Pairs Inequality – that the cost (number of uploaded ciphertexts) for replacing a set of d users in a group of size n is Ω(dln(n/d)). Our lower bound is asymptotically tight and both improves on a bound of Ω(d) by Bienstock et al. (TCC’20), and generalizes a result by Micciancio and Panjwani (Eurocrypt’04), who proved a lower bound of Ω(log(n)) for d=1. }, author = {Anastos, Michael and Auerbach, Benedikt and Baig, Mirza Ahad and Cueto Noval, Miguel and Kwan, Matthew Alan and Pascual Perez, Guillermo and Pietrzak, Krzysztof Z}, booktitle = {22nd International Conference on Theory of Cryptography}, isbn = {9783031780103}, issn = {1611-3349}, location = {Milan, Italy}, pages = {413--443}, publisher = {Springer Nature}, title = {{The cost of maintaining keys in dynamic groups with applications to multicast encryption and group messaging}}, doi = {10.1007/978-3-031-78011-0_14}, volume = {15364}, year = {2024}, } @article{18704, abstract = {Clathrin-mediated endocytosis is the main pathway used by eukaryotic cells to take up extracellular material, but the dominant physical mechanisms driving this process are still elusive. Recently, several high-resolution imaging techniques have been used on different cell lines to measure the geometrical properties of clathrin-coated pits over their whole lifetime. Here, we first show that the combination of all datasets with the recently introduced cooperative curvature model defines a consensus pathway, which is characterized by a flat-to-curved transition at finite area, followed by linear growth and subsequent saturation of curvature. We then apply an energetic model for the composite of the plasma membrane and clathrin coat to this consensus pathway to show that the dominant mechanism for invagination could be coat stiffening, which might originate from cooperative interactions between the different clathrin molecules and progressively drives the system toward its intrinsic curvature. Our theory predicts that two length scales determine the invagination pathway, namely the patch size at which the flat-to-curved transition occurs and the final pit radius.}, author = {Frey, Felix F and Schwarz, Ulrich S.}, issn = {2470-0053}, journal = {Physical Review E}, number = {6}, publisher = {American Physical Society}, title = {{Coat stiffening can explain invagination of clathrin-coated membranes}}, doi = {10.1103/PhysRevE.110.064403}, volume = {110}, year = {2024}, } @article{18708, abstract = {This study investigates the response of Indian summer monsoon (ISM) precipitation to CO2 removal, with a specific focus on regional and subseasonal variations. Following CO2 removal, monsoon circulation weakens throughout the summer owing to the reduced large-scale meridional temperature gradient around India. Weakened monsoon circulation decreases the local-scale thermodynamic stability within India, following monsoon-onset periods. While the frequency of synoptic-scale ISM low-pressure systems (LPSs) decreases overall, the lower thermodynamic stability causes the LPSs to form and resultantly shift west and south from their typical paths, last longer and move more quickly zonally during August and September. Changes in these rain-producing processes induce distinct regional (Western Ghats, south-central-east India, and Tamil Nadu) and subseasonal precipitation responses. Also, extreme precipitation exhibits similar patterns, but is more strongly affected by changes in LPS. Our results suggest that reliable future projections of regional hydroclimate change require a more accurate understanding of multi-scale precipitation processes.}, author = {Paik, Seungmok and Kim, Daehyun and An, Soon Il and Oh, Hyoeun and Shin, Jongsoo and Goswami, Bidyut B and Min, Seung Ki and Mondal, Sanjit Kumar}, issn = {2397-3722}, journal = {npj Climate and Atmospheric Science}, publisher = {Springer Nature}, title = {{Exploring causes of distinct regional and subseasonal Indian summer monsoon precipitation responses to CO2 removal}}, doi = {10.1038/s41612-024-00858-0}, volume = {7}, year = {2024}, } @article{18709, abstract = {We measure the mass distribution of main-sequence (MS) companions to hot subdwarf B stars (sdBs) in post-common envelope binaries (PCEBs). We carried out a spectroscopic survey of 14 eclipsing systems ("HW Vir binaries") with orbital periods of 3.8 < Porb < 12 hr, resulting in a well-understood selection function and a near-complete sample of HW Vir binaries with G < 16. We constrain companion masses from the radial velocity curves of the sdB stars. The companion mass distribution peaks at MMS ≈ 0.15 M⊙ and drops off at MMS > 0.2 M⊙, with only two systems hosting companions above the fully convective limit. There is no correlation between Porb and MMS within the sample. A similar drop-off in the companion mass distribution of white dwarf (WD) + MS PCEBs has been attributed to disrupted magnetic braking (MB) below the fully convective limit. We compare the sdB companion mass distribution to predictions of binary evolution simulations with a range of MB laws. Because sdBs have short lifetimes compared to WDs, explaining the lack of higher-mass MS companions to sdBs with disrupted MB requires MB to be boosted by a factor of 20–100 relative to MB laws inferred from the rotation evolution of single stars. We speculate that such boosting may be a result of irradiation-driven enhancement of the MS stars' winds. An alternative possibility is that common envelope evolution favors low-mass companions in short-period orbits, but the existence of massive WD companions to sdBs with similar periods disfavors this scenario.}, author = {Blomberg, Lisa and El-Badry, Kareem and Breivik, Katelyn and Caiazzo, Ilaria and Nagarajan, Pranav and Rodriguez, Antonio and Van Roestel, Jan and Vanderbosch, Zachary P. and Yamaguchi, Natsuko}, issn = {0004-6280}, journal = {Publications of the Astronomical Society of the Pacific}, number = {12}, publisher = {IOP Publishing}, title = {{The companion mass distribution of post common envelope hot subdwarf binaries: Evidence for boosted and disrupted magnetic braking?}}, doi = {10.1088/1538-3873/ad94a2}, volume = {136}, year = {2024}, } @misc{18716, abstract = {Data for publication 10.1039/d4cp03727h}, author = {Hrast, Mateja}, publisher = {Zenodo}, title = {{Data for: Ab initio Auger spectrum of the ultrafast dissociating 2p3/2−1σ* resonance in HCl}}, doi = {10.5281/ZENODO.13833474}, year = {2024}, } @article{12312, abstract = {Let $\ell$ be a prime number. We classify the subgroups $G$ of $\operatorname{Sp}_4(\mathbb{F}_\ell)$ and $\operatorname{GSp}_4(\mathbb{F}_\ell)$ that act irreducibly on $\mathbb{F}_\ell^4$, but such that every element of $G$ fixes an $\mathbb{F}_\ell$-vector subspace of dimension 1. We use this classification to prove that the local-global principle for isogenies of degree $\ell$ between abelian surfaces over number fields holds in many cases -- in particular, whenever the abelian surface has non-trivial endomorphisms and $\ell$ is large enough with respect to the field of definition. Finally, we prove that there exist arbitrarily large primes $\ell$ for which some abelian surface $A/\mathbb{Q}$ fails the local-global principle for isogenies of degree $\ell$.}, author = {Lombardo, Davide and Verzobio, Matteo}, issn = {1420-9020}, journal = {Selecta Mathematica}, number = {2}, publisher = {Springer Nature}, title = {{On the local-global principle for isogenies of abelian surfaces}}, doi = {10.1007/s00029-023-00908-0}, volume = {30}, year = {2024}, }