@article{17460, abstract = {Filaments in the cell commonly treadmill. Driven by energy consumption, they grow on one end while shrinking on the other, causing filaments to appear motile even though individual proteins remain static. This process is characteristic of cytoskeletal filaments and leads to collective filament self-organization. Here we show that treadmilling drives filament nematic ordering by dissolving misaligned filaments. Taking the bacterial FtsZ protein involved in cell division as an example, we show that this mechanism aligns FtsZ filaments in vitro and drives the organization of the division ring in living Bacillus subtilis cells. We find that ordering via local dissolution also allows the system to quickly respond to chemical and geometrical biases in the cell, enabling us to quantitatively explain the ring formation dynamics in vivo. Beyond FtsZ and other cytoskeletal filaments, our study identifies a mechanism for self-organization via constant birth and death of energy-consuming filaments.}, author = {Vanhille-Campos, Christian Eduardo and Whitley, Kevin D. and Radler, Philipp and Loose, Martin and Holden, Séamus and Šarić, Anđela}, issn = {1745-2481}, journal = {Nature Physics}, pages = {1670--1678}, publisher = {Springer Nature}, title = {{Self-organization of mortal filaments and its role in bacterial division ring formation}}, doi = {10.1038/s41567-024-02597-8}, volume = {20}, year = {2024}, } @article{17461, abstract = {Socially living animals can counteract disease through cooperative defences, leading to social immunity that collectively exceeds the sum of individual defences. In superorganismal colonies of social insects with permanent caste separation between reproductive queen(s) and nonreproducing workers, workers are obligate altruists and thus engage in unconditional social immunity, including highly specialised and self-sacrificial hygiene behaviours. Contrastingly, cooperation is facultative in cooperatively breeding families, where all members are reproductively totipotent but offspring transiently forgo reproduction to help their parents rear more siblings. Here, helpers should either express condition-dependent social immunity or disperse to pursue independent reproduction. We advocate inclusive fitness theory as a framework to predict when and how indirect fitness gains may outweigh direct fitness costs, thus favouring conditional social immunity.}, author = {Cremer, Sylvia and Pull, Christopher}, issn = {1471-5007}, journal = {Trends in Parasitology}, number = {9}, pages = {780--787}, publisher = {Elsevier}, title = {{Unconditional versus condition-dependent social immunity}}, doi = {10.1016/j.pt.2024.07.014}, volume = {40}, year = {2024}, } @article{17462, abstract = {We are interested in numerical algorithms for computing the electrical field generated by a charge distribution localized on scale l in an infinite heterogeneous correlated random medium, in a situation where the medium is only known in a box of diameter L >>l around the support of the charge. We show that the algorithm in [J. Lu, F. Otto, and L. Wang, Optimal Artificial Boundary Conditions Based on Second-Order Correctors for Three Dimensional Random Ellilptic Media, preprint, arXiv:2109.01616, 2021], suggesting optimal Dirichlet boundary conditions motivated by the multipole expansion [P. Bella, A. Giunti, and F. Otto, Comm. Partial Differential Equations, 45 (2020), pp. 561–640], still performs well in correlated media. With overwhelming probability, we obtain a convergence rate in terms of l, L, and the size of the correlations for which optimality is supported with numerical simulations. These estimates are provided for ensembles which satisfy a multiscale logarithmic Sobolev inequality, where our main tool is an extension of the semigroup estimates in [N. Clozeau, Stoch. Partial Differ. Equ. Anal. Comput., 11 (2023), pp. 1254–1378]. As part of our strategy, we construct sublinear second-order correctors in this correlated setting, which is of independent interest.}, author = {Clozeau, Nicolas and Wang, Lihan}, issn = {1540-3467}, journal = {Multiscale Modeling and Simulation}, number = {3}, pages = {973--1029}, publisher = {Society for Industrial and Applied Mathematics}, title = {{Artificial boundary conditions for random elliptic systems with correlated coefficient field}}, doi = {10.1137/23M1603819}, volume = {22}, year = {2024}, } @article{17463, abstract = {Allosteric modulation of protein function, wherein the binding of an effector to a protein triggers conformational changes at distant functional sites, plays a central part in the control of metabolism and cell signalling1,2,3. There has been considerable interest in designing allosteric systems, both to gain insight into the mechanisms underlying such ‘action at a distance’ modulation and to create synthetic proteins whose functions can be regulated by effectors4,5,6,7. However, emulating the subtle conformational changes distributed across many residues, characteristic of natural allosteric proteins, is a significant challenge8,9. Here, inspired by the classic Monod–Wyman–Changeux model of cooperativity10, we investigate the de novo design of allostery through rigid-body coupling of peptide-switchable hinge modules11 to protein interfaces12 that direct the formation of alternative oligomeric states. We find that this approach can be used to generate a wide variety of allosterically switchable systems, including cyclic rings that incorporate or eject subunits in response to peptide binding and dihedral cages that undergo effector-induced disassembly. Size-exclusion chromatography, mass photometry13 and electron microscopy reveal that these designed allosteric protein assemblies closely resemble the design models in both the presence and absence of peptide effectors and can have ligand-binding cooperativity comparable to classic natural systems such as haemoglobin14. Our results indicate that allostery can arise from global coupling of the energetics of protein substructures without optimized side-chain–side-chain allosteric communication pathways and provide a roadmap for generating allosterically triggerable delivery systems, protein nanomachines and cellular feedback control circuitry.}, author = {Pillai, Arvind and Idris, Abbas and Philomin, Annika and Weidle, Connor and Skotheim, Rebecca and Leung, Philip J.Y. and Broerman, Adam and Demakis, Cullen and Borst, Andrew J. and Praetorius, Florian M and Baker, David}, issn = {1476-4687}, journal = {Nature}, pages = {911–920 }, publisher = {Springer Nature}, title = {{De novo design of allosterically switchable protein assemblies}}, doi = {10.1038/s41586-024-07813-2}, volume = {632}, year = {2024}, } @misc{17471, abstract = {Mechanisms for suppressing thermalization in disorder-free many-body systems, such as Hilbert space fragmentation and quantum many-body scars, have recently attracted much interest in foundations of quantum statistical physics and potential quantum information processing applications. However, their sensitivity to realistic effects such as finite temperature remains largely unexplored. Here, we have utilized IBM's Kolkata quantum processor to demonstrate an unexpected robustness of quantum many-body scars at finite temperatures when the system is prepared in a thermal Gibbs ensemble. We identify such robustness in the PXP model, which describes quantum many-body scars in experimental systems of Rydberg atom arrays and ultracold atoms in tilted Bose--Hubbard optical lattices. By contrast, other theoretical models which host exact quantum many-body scars are found to lack such robustness, and their scarring properties quickly decay with temperature. Our study sheds light on the important differences between scarred models in terms of their algebraic structures, which impacts their resilience to finite temperature.}, author = {Desaules, Jean-Yves Marc}, keywords = {quantum many-body scars, non-equilibrium physics, non-Hermitian physics}, publisher = {Institute of Science and Technology Austria}, title = {{Data for "Enhanced many-body quantum scars from the non-Hermitian Fock skin effect"}}, doi = {10.15479/AT:ISTA:17471}, year = {2024}, } @article{17474, abstract = {Entropic risk (ERisk) is an established risk measure in finance, quantifying risk by an exponential re-weighting of rewards. We study ERisk for the first time in the context of turn-based stochastic games with the total reward objective. This gives rise to an objective function that demands the control of systems in a risk-averse manner. We show that the resulting games are determined and, in particular, admit optimal memoryless deterministic strategies. This contrasts risk measures that previously have been considered in the special case of Markov decision processes and that require randomization and/or memory. We provide several results on the decidability and the computational complexity of the threshold problem, i.e. whether the optimal value of ERisk exceeds a given threshold. Furthermore, an approximation algorithm for the optimal value of ERisk is provided.}, author = {Baier, Christel and Chatterjee, Krishnendu and Meggendorfer, Tobias and Piribauer, Jakob}, issn = {1090-2651}, journal = {Information and Computation}, publisher = {Elsevier}, title = {{Entropic risk for turn-based stochastic games}}, doi = {10.1016/j.ic.2024.105214}, volume = {301}, year = {2024}, } @article{17475, abstract = {As a discrete analogue of Kac’s celebrated question on ‘hearing the shape of a drum’ and towards a practical graph isomorphism test, it is of interest to understand which graphs are determined up to isomorphism by their spectrum (of their adjacency matrix). A striking conjecture in this area, due to van Dam and Haemers, is that ‘almost all graphs are determined by their spectrum’, meaning that the fraction of unlabelled n-vertex graphs which are determined by their spectrum converges to 1 as n → ∞. In this paper, we make a step towards this conjecture, showing that there are exponentially many n-vertex graphs which are determined by their spectrum. This improves on previous bounds (of shape e c √ n ). We also propose a number of further directions of research. }, author = {Koval, Illya and Kwan, Matthew Alan}, issn = {1464-3847}, journal = {Quarterly Journal of Mathematics}, number = {3}, pages = {869--899}, publisher = {Oxford University Press}, title = {{Exponentially many graphs are determined by their spectrum}}, doi = {10.1093/qmath/haae030}, volume = {75}, year = {2024}, } @article{17476, abstract = {Lead halide perovskites have recently been reported to demonstrate an exceptionally high nonlinear (Kerr) refractive index n2 of up to 10−8cm2/W in CH3⁢NH3⁢PbBr3. Other researchers, however, observe different, substantially more conservative numbers. In order to resolve this disagreement, the nonlinear Kerr index of a bulk sample of lead halide perovskite was measured directly by means of an interferometer. This approach has many advantages as compared to the more standard z-scan technique. In particular, this method allows studying the induced changes to the refractive index in a time-resolved manner, thus enabling to separate the different contributions to 𝑛2. The extracted 𝑛2 values for CsPbBr3 and MAPbBr3 at 𝜆≈1µ⁢m are 𝑛2=+2.1×10−14cm2/W and 𝑛2=+6×10−15cm2/W, respectively. Hence, these values are substantially lower than what has been indicated in most of the previous reports, implying the latter one should be regarded with great care.}, author = {Lorenc, Dusan and Zhumekenov, Ayan and Bakr, Osman M. and Alpichshev, Zhanybek}, issn = {2475-9953}, journal = {Physical Review Materials}, number = {8}, publisher = {American Physical Society}, title = {{No extraordinary χ(3) in lead-halide perovskites: Placing an upper bound on Kerr nonlinearity by means of time-resolved interferometry}}, doi = {10.1103/PhysRevMaterials.8.085403}, volume = {8}, year = {2024}, } @article{17477, abstract = {Trapped-ion systems are a leading platform for quantum information processing, but they are currently limited to 1D and 2D arrays, which imposes restrictions on both their scalability and their range of applications. Here, we propose a path to overcome this limitation by demonstrating that Penning traps can be used to realize remarkably clean bilayer crystals, wherein hundreds of ions self-organize into two well-defined layers. These bilayer crystals are made possible by the inclusion of an anharmonic trapping potential, which is readily implementable with current technology. We study the normal modes of this system and discover salient differences compared to the modes of single-plane crystals. The bilayer geometry and the unique properties of the normal modes open new opportunities—in particular, in quantum sensing and quantum simulation—that are not straightforward in single-plane crystals. Furthermore, we illustrate that it may be possible to extend the ideas presented here to realize multilayer crystals with more than two layers. Our work increases the dimensionality of trapped-ion systems by efficiently utilizing all three spatial dimensions, and it lays the foundation for a new generation of quantum information processing experiments with multilayer 3D crystals of trapped ions.}, author = {Hawaldar, Samarth and Shahi, Prakriti and Carter, Allison L. and Rey, Ana Maria and Bollinger, John J. and Shankar, Athreya}, issn = {2160-3308}, journal = {Physical Review X}, number = {3}, publisher = {American Physical Society}, title = {{Bilayer crystals of trapped ions for quantum information processing}}, doi = {10.1103/PhysRevX.14.031030}, volume = {14}, year = {2024}, } @article{17478, abstract = {We study the Fröhlich polaron model in R3, and prove a lower bound on its ground state energy as a function of the total momentum. The bound is asymptotically sharp at large coupling. In combination with a corresponding upper bound proved earlier (Mitrouskas et al. in Forum Math. Sigma 11:1–52, 2023), it shows that the energy is approximately parabolic below the continuum threshold, and that the polaron’s effective mass (defined as the semi-latus rectum of the parabola) is given by the celebrated Landau–Pekar formula. In particular, it diverges as α4 for large coupling constant α.}, author = {Brooks, Morris and Seiringer, Robert}, issn = {1618-1913}, journal = {Publications Mathematiques de l'Institut des Hautes Etudes Scientifiques}, pages = {271--309}, publisher = {Springer Nature}, title = {{The Fröhlich polaron at strong coupling: Part II — Energy-momentum relation and effective mass}}, doi = {10.1007/s10240-024-00150-0}, volume = {140}, year = {2024}, } @article{17479, abstract = {Phonon polaritons (PhPs), light coupled to lattice vibrations, in the highly anisotropic polar layered material molybdenum trioxide (α-MoO3) are currently the focus of intense research efforts due to their extreme subwavelength field confinement, directional propagation, and unprecedented low losses. Nevertheless, prior research has primarily concentrated on exploiting the squeezing and steering capabilities of α-MoO3 PhPs, without inquiring much into the dominant microscopic mechanism that determines their long lifetimes, which is key for their implementation in nanophotonic applications. This study delves into the fundamental processes that govern PhP damping in α-MoO3 by combining ab initio calculations with scattering-type scanning near-field optical microscopy (s-SNOM) and Fourier transform infrared (FTIR) spectroscopy measurements across a broad temperature range (8–300 K). The remarkable agreement between our theoretical predictions and experimental observations allows us to identify third-order anharmonic phonon–phonon scattering as the main damping mechanism of α-MoO3 PhPs. These findings shed light on the fundamental limits of low-loss PhPs, which is a crucial factor for assessing their implementation into nanophotonic devices.}, author = {Taboada-Gutiérrez, Javier and Zhou, Yixi and Tresguerres-Mata, Ana I.F. and Lanza, Christian and Martínez-Suárez, Abel and Álvarez-Pérez, Gonzalo and Duan, Jiahua and Martín, José Ignacio and Vélez, María and Prieto Gonzalez, Ivan and Bercher, Adrien and Teyssier, Jérémie and Errea, Ion and Nikitin, Alexey Y. and Martín-Sánchez, Javier and Kuzmenko, Alexey B. and Alonso-González, Pablo}, issn = {2330-4022}, journal = {ACS Photonics}, number = {9}, pages = {3570--3577}, publisher = {American Chemical Society}, title = {{Unveiling the mechanism of phonon-polariton damping in α‑MoO3}}, doi = {10.1021/acsphotonics.4c00485}, volume = {11}, year = {2024}, } @article{17480, abstract = {One of the most promising approaches towards large-scale quantum computation uses devices based on many Josephson junctions. Yet, even today, open questions regarding the single junction remain unsolved, such as the detailed understanding of the quantum phase transitions, the coupling of the Josephson junction to the environment or how to improve the coherence of a superconducting qubit. Here we design and build an engineered on-chip reservoir connected to a Josephson junction that acts as an efficient bolometer for detecting the Josephson radiation under non-equilibrium, that is, biased conditions. The bolometer converts the a.c. Josephson current at microwave frequencies up to about 100 GHz into a temperature rise measured by d.c. thermometry. A circuit model based on realistic parameter values captures both the current–voltage characteristics and the measured power quantitatively. The present experiment demonstrates an efficient, wide-band, thermal detection scheme of microwave photons and provides a sensitive detector of Josephson dynamics beyond the standard conductance measurements.}, author = {Karimi, Bayan and Steffensen, Gorm Ole and Higginbotham, Andrew P and Marcus, Charles M. and Levy Yeyati, Alfredo and Pekola, Jukka P.}, issn = {1748-3395}, journal = {Nature Nanotechnology}, pages = {1613--1618}, publisher = {Springer Nature}, title = {{Bolometric detection of Josephson radiation}}, doi = {10.1038/s41565-024-01770-7}, volume = {19}, year = {2024}, } @article{17481, abstract = {Phase-field models such as the Allen–Cahn equation may give rise to the formation and evolution of geometric shapes, a phenomenon that may be analyzed rigorously in suitable scaling regimes. In its sharp-interface limit, the vectorial Allen–Cahn equation with a potential with N≥3 distinct minima has been conjectured to describe the evolution of branched interfaces by multiphase mean curvature flow. In the present work, we give a rigorous proof for this statement in two and three ambient dimensions and for a suitable class of potentials: as long as a strong solution to multiphase mean curvature flow exists, solutions to the vectorial Allen–Cahn equation with well-prepared initial data converge towards multiphase mean curvature flow in the limit of vanishing interface width parameter ε↘0. We even establish the rate of convergence O(ε 1/2 ). Our approach is based on the gradient-flow structure of the Allen–Cahn equation and its limiting motion: building on the recent concept of “gradient-flow calibrations” for multiphase mean curvature flow, we introduce a notion of relative entropy for the vectorial Allen–Cahn equation with multi-well potential. This enables us to overcome the limitations of other approaches, e.g. avoiding the need for a stability analysis of the Allen–Cahn operator or additional convergence hypotheses for the energy at positive times.}, author = {Fischer, Julian L and Marveggio, Alice}, issn = {1873-1430}, journal = {Annales de l'Institut Henri Poincare C}, number = {5}, pages = {1117--1178}, publisher = {EMS Press}, title = {{Quantitative convergence of the vectorial Allen–Cahn equation towards multiphase mean curvature flow}}, doi = {10.4171/AIHPC/109}, volume = {41}, year = {2024}, } @misc{17488, abstract = {Behavioural data for Pokusaeva, Satapathy et al. Relevant information can be found in the 'README.txt' file.}, author = {Satapathy, Roshan K and Jösch, Maximilian A and Symonova, Olga and Pokusaeva, Victoria}, keywords = {drosophila, behaviour, locomotion, gap junctions}, publisher = {Institute of Science and Technology Austria}, title = {{Bilateral interactions of optic-flow sensitive neurons coordinate course control in flies}}, doi = {10.15479/AT:ISTA:17488}, year = {2024}, } @article{17493, abstract = {Estimating global properties of many-body quantum systems such as entropy or bipartite entanglement is a notoriously difficult task, typically requiring a number of measurements or classical postprocessing resources growing exponentially in the system size. In this work, we address the problem of estimating global entropies and mixed-state entanglement via partial-transposed (PT) moments and show that efficient estimation strategies exist under the assumption that all the spatial correlation lengths are finite. Focusing on one-dimensional systems, we identify a set of approximate factorization conditions (AFCs) on the system density matrix, which allow us to reconstruct entropies and PT moments from information on local subsystems. This identification yields a simple and efficient strategy for entropy and entanglement estimation. Our method could be implemented in different ways, depending on how information on local subsystems is extracted. Focusing on randomized measurements providing a practical and common measurement scheme, we prove that our protocol requires only polynomially many measurements and postprocessing operations, assuming that the state to be measured satisfies the AFCs. We prove that the AFCs hold for finite-depth quantum-circuit states and translation-invariant matrix-product density operators and provide numerical evidence that they are satisfied in more general, physically interesting cases, including thermal states of local Hamiltonians. We argue that our method could be practically useful to detect bipartite mixed-state entanglement for large numbers of qubits available in today’s quantum platforms.}, author = {Vermersch, Benoît and Ljubotina, Marko and Cirac, J. Ignacio and Zoller, Peter and Serbyn, Maksym and Piroli, Lorenzo}, issn = {2160-3308}, journal = {Physical Review X}, number = {3}, publisher = {American Physical Society}, title = {{Many-body entropies and entanglement from polynomially many local measurements}}, doi = {10.1103/physrevx.14.031035}, volume = {14}, year = {2024}, } @article{17494, author = {Bravo, Jack Peter Kelly}, issn = {1746-0921}, journal = {Future Microbiology}, number = {15}, pages = {1269--1272}, publisher = {Taylor & Francis}, title = {{Anti-plasmid immunity: A key to pathogen success?}}, doi = {10.1080/17460913.2024.2389720}, volume = {19}, year = {2024}, } @article{17495, abstract = {Rust is a modern systems programming language whose ownership-based type system statically guarantees memory safety, making it particularly well-suited to the domain of safety-critical systems. In recent years, a wellspring of automated deductive verification tools have emerged for establishing functional correctness of Rust code. However, none of the previous tools produce foundational proofs (machine-checkable in a general-purpose proof assistant), and all of them are restricted to the safe fragment of Rust. This is a problem because the vast majority of Rust programs make use of unsafe code at critical points, such as in the implementation of widely-used APIs. We propose RefinedRust, a refinement type system—proven sound in the Coq proof assistant—with the goal of establishing foundational semi-automated functional correctness verification of both safe and unsafe Rust code. We have developed a prototype verification tool implementing RefinedRust. Our tool translates Rust code (with user annotations) into a model of Rust embedded in Coq, and then checks its adherence to the RefinedRust type system using separation logic automation in Coq. All proofs generated by RefinedRust are checked by the Coq proof assistant, so the automation and type system do not have to be trusted. We evaluate the effectiveness of RefinedRust by verifying a variant of Rust’s Vec implementation that involves intricate reasoning about unsafe pointer-manipulating code.}, author = {Gäher, Lennard and Sammler, Michael Joachim and Jung, Ralf and Krebbers, Robbert and Dreyer, Derek}, issn = {2475-1421}, journal = {Proceedings of the ACM on Programming Languages}, number = {PLDI}, pages = {1115--1139}, publisher = {Association for Computing Machinery}, title = {{RefinedRust: A type system for high-assurance verification of rust programs}}, doi = {10.1145/3656422}, volume = {8}, year = {2024}, } @article{17497, abstract = {Over the past two decades, there has been a great deal of progress on verification of full functional correctness of programs using separation logic, sometimes even producing “foundational” proofs in proof assistants like Coq. Unfortunately, even though existing approaches to this problem provide significant support for automated verification, they still incur a significant specification overhead: the user must supply the specification against which the program is verified, and the specification may be long, complex, or tedious to formulate. In this paper, we introduce Quiver, the first technique for inferring functional correctness specifications in separation logic while simultaneously verifying foundationally that they are correct. To guide Quiver towards the final specification, we take hints from the user in the form of a specification sketch, and then complete the sketch using inference. To do so, Quiver introduces a new abductive deductive verification technique, which integrates ideas from abductive inference (for specification inference) together with deductive separation logic automation (for foundational verification). The result is that users have to provide some guidance, but significantly less than with traditional deductive verification techniques based on separation logic. We have evaluated Quiver on a range of case studies, including code from popular open-source libraries.}, author = {Spies, Simon and Gäher, Lennard and Sammler, Michael Joachim and Dreyer, Derek}, issn = {2475-1421}, journal = {Proceedings of the ACM on Programming Languages}, number = {PLDI}, pages = {889--913}, publisher = {Association for Computing Machinery}, title = {{Quiver: Guided abductive inference of separation logic specifications in coq}}, doi = {10.1145/3656413}, volume = {8}, year = {2024}, } @article{17517, abstract = {We present an analysis of NuSTAR X-ray observations of three active galactic nuclei (AGN) that were identified as candidate subparsec binary supermassive black hole (SMBH) systems in the Catalina Real-Time Transient Survey based on apparent periodicity in their optical light curves. Simulations predict that close-separation accreting SMBH binaries will have different X-ray spectra than single accreting SMBHs. We previously observed these AGN with Chandra and found no differences between their low-energy X-ray properties and the larger AGN population. However, some models predict differences to be more prominent at energies higher than probed by Chandra. We find that even at the higher energies probed by NuSTAR, the spectra of these AGN are indistinguishable from the larger AGN population. This could rule out models predicting large differences in the X-ray spectra in the NuSTAR bands. Alternatively, it might mean that these three AGN are not binary SMBHs.}, author = {Saade, M. Lynne and Brightman, Murray and Stern, Daniel and Connor, Thomas and Djorgovski, S. G. and D’Orazio, Daniel J. and Ford, K. E. S. and Graham, Matthew J. and Haiman, Zoltán and Jun, Hyunsung D. and Kammoun, Elias and Kraft, Ralph P. and McKernan, Barry and Vikhlinin, Alexei and Walton, Dominic J.}, issn = {0004-637X}, journal = {The Astrophysical Journal}, number = {1}, publisher = {American Astronomical Society}, title = {{NuSTAR observations of candidate subparsec binary supermassive black holes}}, doi = {10.3847/1538-4357/ad372e}, volume = {966}, year = {2024}, } @article{17531, abstract = {The astrophysical origin of stellar-mass black hole (BH) mergers discovered through gravitational waves (GWs) is widely debated. Mergers in the disks of active galactic nuclei (AGNs) represent promising environments for at least a fraction of these events, with possible observational clues in the GW data. An additional clue to unveil AGN merger environments is provided by possible electromagnetic emission from postmerger accreting BHs. Associated with BH mergers in AGN disks, emission from shocks emerging around jets launched by accreting merger remnants is expected. Here we compute the properties of the emission produced during breakout and the subsequent adiabatic expansion phase of the shocks, and we then apply this model to optical flares suggested to be possibly associated with GW events. We find that the majority of the reported flares can be explained by breakout and shock cooling emission. If the optical flares are produced by shock cooling emission, they would display moderate color evolution, possibly color variations among different events, and a positive correlation between delay time and flare duration and would be preceded by breakout emission in X-rays. If the breakout emission dominates the observed lightcurve, we predict the color to be distributed in a narrow range in the optical band and the delay time from GW to electromagnetic emission to be longer than ∼2 days. Hence, further explorations of delay time distributions, flare color evolution, and associated X-ray emission will be useful to test the proposed emission model for the observed flares.}, author = {Tagawa, Hiromichi and Kimura, Shigeo S and Haiman, Zoltán and Perna, Rosalba and Bartos, Imre}, issn = {0004-637X}, journal = {The Astrophysical Journal}, number = {1}, publisher = {American Astronomical Society}, title = {{Shock cooling and breakout emission for optical flares associated with gravitational-wave events}}, doi = {10.3847/1538-4357/ad2e0b}, volume = {966}, year = {2024}, }