High Energy Physics (Phenomenology)
The Challenge of Detecting Quantum Nature of Gravitational Waves
Yu Miyauchi, Hidetoshi Omiya, Atsuhisa Ota et al. (+2 more)
We investigate whether squeezing can provide an observable signature of
quantum gravitational waves. Because a realistic detector couples only to a particular wave-packet mode, squeezing in global source modes need not remain observable. We show that inflationary two-mode squeezing reduces to an unsqueezed thermal state in the accessible one-mode sector, phase incoherence washes out squeezing in
stochastic backgrounds, and the limited coverage of the solid angle of detectors strongly suppresses squeezing from isolated sources. We then show that source squeezing is not essential, i.e., a quantized gravitational wave can generate a positive squeezing witness if the detector state is initially prepared in a squeezed state, whereas a classical external gravitational field cannot, producing only a displacement. However, the resulting signal is bounded by the extremely small graviton–detector coupling. Thus, detector squeezing can remove the need for squeezed incident waves, but not the suppression caused by weak gravitational interaction.
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All authors Yu Miyauchi, Hidetoshi Omiya, Atsuhisa Ota, Hiroki Takeda, Takahiro Tanaka
Quantum Physics
Symmetry Constraints Regularize Neural Quantum State Learning
Turbasu Chatterjee, Manas Sajjan, Songbo Xie et al. (+4 more)
Neural
quantum states (NQS) offer highly expressive variational wavefunctions, but their optimization is frequently bottlenecked by redundant parameters and poorly conditioned landscapes. We demonstrate that
embedding Hamiltonian symmetries directly into the variational parameterization geometrically regularizes this learning problem. For Boltzmann-family NQS, we enforce
symmetries by tying local Pauli-$Z$ generators along physical
geometric orbits, analytically collapsing the trainable coefficient space prior to optimization. To quantify the resulting optimization geometry, we introduce a
geometric metric built on the Jacobian and Hessian of the optimization landscape. This framework evaluates the fraction of the physically accessible state space that corresponds to high-quality, low-energy solutions. Evaluating our approach on transverse-field Ising (TFIM) and XXZ
spin chains shows that
symmetry compilation excises the vast majority of parameters while maintaining ground-state accuracy within the resolution of the reported
benchmarks. In large TFIM systems, strong spatial constraints compress thousands of parameters down to tens, delivering substantial runtime accelerations. Our
geometric diagnostics indicate that
symmetry produces a more favorable target-aware geometry by concentrating the reachable state space around low-energy solutions while retaining broad target basins. Together, our results indicate that
symmetry compilation concentrates the expressive power of NQS on states relevant to the target problem, thereby reducing model size and training cost without sacrificing accuracy.
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All authors Turbasu Chatterjee, Manas Sajjan, Songbo Xie, Elliott Love, Vinit Singh, Bojko N. Bakalov, Sabre Kais
High Energy Physics (Theory)
Running soft theorems in effective field theory
Jonah Berean-Dutcher, Maria Derda and Riley Stewart
We study soft
theorems for
photons and pions with local effective field theory (EFT) corrections up to one loop order. In massive QED with a dimension-five Pauli operator, the local analytic part of the subleading soft
photon theorem is renormalized by the hard integration region. On the other hand, as was previously known, the logarithmic soft terms do not receive corrections from higher-dimensional operators. We find that analogous structure appears in the double-soft pion
theorem: the coefficients of logarithmic contributions are controlled entirely by the Nonlinear Sigma Model (NLSM) Lagrangian, while the Wilson coefficients of four-derivative operators in
Chiral EFT appear in local subleading terms, in a form that is dictated by their RG equations.
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Chemical Physics
Self-consistent double-hybrid density functional theory via one-body second-order Møller-Plesset perturbation theory and projection-based embedding
Huy Gia Bui and Lan Nguyen Tran
We present the development of self-consistent one-body double-hybrid (OBDH) density functional theory (DFT). In this approach, the one-body second-order Møller-Plesset (OBMP2) perturbation potential is embedded directly in the generalized Kohn-Sham framework, allowing orbitals to be optimized in the presence of MP2-level dynamic correlation. Unlike existing orbital-optimized double hybrids, OBDH requires neither the optimized effective potential nor perturbative orbital relaxation corrections. The energy functional combines a semilocal exchange-correlation functional, exact exchange, and OBMP2 correlation, from which the effective
Hamiltonian and self-consistent-field equations are systematically derived. To reduce computational cost, projector-based
embedding with concentric localization truncation is applied to the OBMP2 component, termed sub-OBDH. OBDH and sub-OBDH are benchmarked on diatomic potential energy curves, self-interaction errors, dihedral torsions of organic molecules, and interaction energies in non-covalent charged systems. Across all systems, OBDH consistently outperforms standard DFT, demonstrating its potential for accurate and practical electronic structure calculations.
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High Energy Physics (Theory)
3d $\mathcal N=4$ rank-zero mirror symmetry, TQFT interfaces, and Zagier duality of Nahm sums
Yutaka Yoshida
Starting from the $(E_8,T_1)$ Nahm sum for the
vacuum character of $T_{10}M_{\rm eff}(11,2)$, we construct a three-dimensional (3d) $\mathcal N=2$ $U(1)^8$ Chern–Simons matter theory $\mathcal T$ with level
matrix $C_{E_8}$. Its $A$-twisted
vacuum half-index reproduces the character exactly, while four distinguished Wilson loop half-indices agree with the remaining characters to the orders checked. Applying particle–
vortex duality and gauging yields a second 3d $\mathcal N=2$ Chern–Simons matter theory $\mathcal T^\vee$ with level
matrix $C_{E_8}^{-1}$. Exact superconformal-index matching supports the claim that the two theories flow to 3d $\mathcal N=4$ rank-zero mirror SCFTs. For the $(\mathcal D,D_c)$ boundary condition, the mirror map between the $A$-twisted Wilson loop half-indices of $\mathcal T$ and the $B$-twisted Wilson loop half-indices of $\mathcal T^\vee$ coincides componentwise with the Zagier transformation, realizing a Zagier duality between the complete $(E_8,T_1)$ and $(T_1,E_8)$ Nahm systems. Using the Bethe-equation formalism, we show that the corresponding $A/B$-twisted TQFT data agree up to orientation reversal and the $E_8$ framing phase $e^{-2\pi \mathrm{i}/3}$. The duality interface gives the
torus bilinear $Z_{\mathcal I}(\tau)=\sum_i\chi_i(\tau)\chi_i^\vee(\tau)=\chi_{(E_8)_1}(\tau)$, where $\{\chi_i\}$ and $\{\chi_i^\vee\}$ are the corresponding five-component character bases. Thus Zagier duality is realized as part of a concrete 3d mirror and interface structure.
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Quantum Physics
How to Test Bell Nonlocality for Gravity?
Debarshi Das, Mir Alimuddin, Simon Storz et al. (+2 more)
We propose an experiment to test Bell nonlocality, a genuine nonclassicality, for the gravitational field. Two masses with embedded entangled
spins (e.g., two diamonds with their NV-centre
spins entangled) are placed well outside each other's light cones, ensuring a locality-loophole-free scenario. The
spins are then coupled to the motion of their respective masses to generate spatial superpositions. Finally, local measurements are performed only on the gravitational fields of the two masses. If
gravity is
quantum, then the two entangled masses would entangle their gravitational fields, leading to correlations certifying Bell nonlocality of
gravity. Trapped and ground-state cooled nano-objects with micron-sized spatial superposition are sufficient for this test. This goes beyond the recent proposals to test nonclassicality of
gravity by providing, for the first time in the literature, a minimal tool to (i) create Einstein-Podolsky-Rosen (EPR) state of gravitational
curvatures, (ii) witness entangled gravitational
curvatures, (iii) rule out any local-realist description of
gravity, and (iv) achieve a loophole-free test of
gravity's nonclassicality in a fully device-independent way.
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All authors Debarshi Das, Mir Alimuddin, Simon Storz, Yiwen Chu, Sougato Bose
Exactly Solvable and Integrable Systems
A. Zabrodin
A class of
elliptic solutions to the
matrix CKP equation is studied. Equations of motion for their poles and
matrix coefficients at the poles are obtained. As in the scalar case, they are of the first order, in contrast to what takes place in the KP and BKP hierarchies, where the equations of motion are of the second order.
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High Energy Physics (Phenomenology)
Near-threshold resonances in $e^+e^-$ annihilation
S.G. Salnikov, A.E. Bondar and A.I. Milstein
Near-threshold resonances have been discovered in many
hadron pair production processes, resulting in a significant increase in reaction cross sections at low relative velocities of the produced particles. The natural cause of such resonances is the interaction between slow
hadrons in the final state. Our review demonstrates that, in virtually all known cases, final-state interactions successfully explain the results of numerous experiments demonstrating a nontrivial energy dependence of cross sections for processes near reaction thresholds. A comprehensive study of near-threshold resonances in various processes can provide new information about the interaction between
hadrons at large distances.
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Materials Science
Distribution of Relaxation Times analysis of evolution of Oxygen Reduction Pathways for ionic conductor infiltration on MIEC cathode
Rakhi Saha, Preethi Sudarsan, Manju Kumari et al. (+4 more)
Solid
oxide fuel
cells (SOFCs) are promising electrochemical energy conversion devices; however, the sluggish cathodic oxygen reduction reaction (ORR) remains a major limitation for intermediate-temperature operation. ORR subprocesses can be modified by infiltrating ionic Sm0.2Ce0.8O2-delta (SDC) on mixed ionic electronic SrFe0.9Ti0.1O3-delta (STF). However, the processes are indistinguishable in most cases and poorly understood using conventional equivalent
circuits. Distribution of Relaxation Times (DRT) analysis distinguishes these processes to identify the dynamics with temperature and surface reconstruction. Such analysis is being reported, revealing the connection between increase of active sites, temperature, and polarization resistance (RP). SDC infiltration preferentially accelerates oxygen surface exchange and activation processes over the relatively high frequency charge transfer process related to cathode surface at elevated temperatures for the infiltrated
cells. RP was reduced substantially with the systematic redistribution of each process to as low as 0.04 ohm.cm2 at 800 degC. This work underlines the deconvolution of the processes using DRT as a tool, and SDC infiltrated STF as a model cathode system to provide a mechanistic insight of understanding ORR kinetics and design a rationale for developing high-performance SOFC air electrodes
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All authors Rakhi Saha, Preethi Sudarsan, Manju Kumari, Hee Jung Park, Abdelkrim Mekki, Khalil Harrabi, Somaditya Sen
High Energy Physics (Theory)
Understanding Non-Split 2-Group Symmetry: (3+1)D SymTFT, Anomaly and Bordism
Zhenbang Gu, Ran Luo, Yi-Nan Wang et al. (+1 more)
We present a systematic study of finite, non-split 2-group
symmetries with a non-trivial Postnikov class, focusing on the simplest example with a $\mathbb{Z}_2$ 0-form
symmetry and a $\mathbb{Z}_2$ 1-form
symmetry, intertwined together by the non-trivial Postnikov class in $H^3(B\mathbb{Z}_2;\mathbb{Z}_2)\cong\mathbb{Z}_2$, denoted by $\mathcal{G}$. We classify the anomalies of this 2-group
symmetry for physical theories in $d$-dimensional spacetime, by computing the oriented bordism groups $\Omega_{d+1}^{\rm SO}(B\mathcal{G})$ and the
spin bordism groups $\Omega_{d+1}^{\rm Spin}(B\mathcal{G})$ for $d\leq 5$. For the case of $d=3$, we investigate the
Symmetry TFT/TO of the 2-group
symmetry $\mathcal{G}$ using the
language of fusion 2-categories, as well as (3+1)D TQFT actions, for the cases without or with the 2-group anomaly classified by $\operatorname{Hom}\left(\widetilde{\Omega}_4^{\rm SO}(B\mathcal{G}),U(1)\right) \cong H^4(B\mathcal{G};U(1))\cong\mathbb{Z}_2$. We classify the minimal topological and physical boundary conditions of the
Symmetry TFTs, and carry out the categorical Landau paradigm for such a non-split finite 2-group.
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All authors Zhenbang Gu, Ran Luo, Yi-Nan Wang, Yi Zhang
Quantum Physics · Cross-listed from cs.PL
Bona: Automatic Management of Dirty Ancilla Borrowing in Quantum Circuits
Xiaoquan Xu, Chenke Liu, Boning Meng et al. (+2 more)
The management of ancilla
qubits has become a critical technique for reducing
quantum circuit width. Dirty ancillas, which may be borrowed from any temporarily idle
qubit regardless of their initial states, offer substantial flexibility for width optimization, but their use has so far required manual and error-prone handling. We formalize the dirty-
qubit borrowing problem and establish a fundamental computational limit by proving its NP-hardness. To support practical optimization, we present \bona, the first scheduler for dirty-
qubit borrowing, built on a novel depth-aware heuristic
algorithm. We evaluate \bona~ across a variety of
benchmarks, including practical
quantum circuits and randomly arranged compositions of real
circuit modules, and find that it reduces nearly 99% of dirty ancillas on average with controlled depth overhead. In particular, for parallel
quantum walk—an essential component of parallel
Hamiltonian simulation—\bona~ matches the
circuit width achieved by the clean-
qubit schemes of \citeauthor{jiang2024recycling}~(\citeyear{jiang2024recycling}) and \citeauthor{quantinuum}~(\citeyear{quantinuum}), but attains significantly smaller
circuit depth, providing concrete evidence that dirty ancillas offer unique optimization advantages in
circuits with certain parallelism.
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All authors Xiaoquan Xu, Chenke Liu, Boning Meng, Zihao Shen, Li Zhou
Fluid Dynamics
Turbulence anisotropy in a bubbly vertical channel flow with topological change
Arturo A. Arosemena, Davide Procacci, Simone Di Giorgio et al. (+2 more)
High-fidelity numerical simulations of bubble-laden, vertical channel flow in the upward configuration, where the bubbles undergo topological changes (breakup and coalescence), were performed with the purpose of exploring the effect of the surface tension on the
turbulence anisotropy in the carrier phase. A qualitative analysis shows that velocity fluctuations are enhanced in the wake of large bubbles. Moreover, as shown by the velocity spectra, these structures seem to scale with bubble size and interact with those closer to the wall. Finally, a barycentric map and other indicators of
turbulence anisotropy clarify that, except at the core of the channel where the largest bubbles reside, the multiphase flow cases are actually more isotropic than the single-phase flow at a matching friction Reynolds number. This unexpected behavior is attributed to a better redistribution of energy due to an enhancement of sweep events (high-speed fluid towards the wall) in the presence of large bubbles.
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All authors Arturo A. Arosemena, Davide Procacci, Simone Di Giorgio, Jannike Solsvik, Shahab Mirjalili
High Energy Physics (Phenomenology)
Comment on "Regarding the Rotational Unruh Effect"
S. R. Mane
We comment on various statements in a recent document (A.~Deur, S.~J.~Brodsky, C.~D.~Roberts and B.~Terzić, Regarding the Rotational Unruh Effect, arXiv:2607.25004v1 [hep.ph], (2026)). The examples cited treat electrons (or positrons) circulating and emitting
photons in high-energy storage rings. The topic is also of interest in astrophysics, for electrons orbiting in
magnetic fields around
neutron stars.
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Chemical Physics
Analytical Nuclear Gradients and Hessians on Quantum Hardware via Orbital-Optimized VQE with Error Mitigation
Renato Olarte Hernandez, Karl Michael Ziems, Erik Kjellgren et al. (+3 more)
Nuclear gradients and Hessians are fundamental quantities in computational chemistry, essential for a wide range of applications including geometry optimization, vibrational spectroscopy, and molecular property calculations. In this work, we present their analytical implementation on
quantum hardware. The methodology is formulated within an active-space framework combining orbital optimization and linear-response theory. On the
quantum-computing side, the approach employs the tiled
unitary product state (tUPS) ansatz to directly evaluate the tensor elements required for solving the response equations. Moreover, the expectation values are corrected using an adapted confusion-
matrix error-mitigation scheme in combination with post-selection criteria. The resulting workflow is assessed on molecular hydrogen and on water through the calculation of potential energy surfaces,
nuclear gradients, Hessians, and vibrational frequencies, enabling the evaluation of both its capabilities and current limitations. The results demonstrate good performance for the hydrogen molecule, whereas the water molecule provides a more demanding test of
quantum-hardware resources and highlights the trade-offs associated with error-mitigation strategies. The quantified analysis of the results identify the main sources of errors, suggesting improvement directions for more accurate
quantum computer applications.
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All authors Renato Olarte Hernandez, Karl Michael Ziems, Erik Kjellgren, Jacob Kongsted, Sonia Coriani, Stephan P. A. Sauer
High Energy Astrophysical Phenomena
Timing and statistical analysis of single-pulse search pulsar discoveries from the PALFA survey
Graham M. Doskoch, Maura A. McLaughlin, B. Allen et al. (+23 more)
Almost two decades after their discovery,
pulsars discoverable only through their single, dispersed
radio pulses, known as rotating
radio transients (RRATS), remain a poorly-understood class of objects. Compared to the overall
pulsar population, few have timing solutions, limiting our ability to understand the mechanisms underlying their sporadic emission. Here, we present a single-pulse analysis of twelve sources from the PALFA survey, consisting of eleven objects initially identified as RRATs and one candidate fast
radio burst. We present timing solutions for five of the sources with detections at a sufficient number of epochs and
spin periods for two more. For all sources, we use a
Bayesian framework to fit distributions of single-pulse energies, finding support for log-normal energy distributions and pulse-to-pulse wait times that are consistent with Poisson processes. Finally, we provide updates on the previously-published candidate fast
radio burst J0613+18, with new indications that it is in fact extragalactic.
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All authors Graham M. Doskoch, Maura A. McLaughlin, B. Allen, A. Brazier, F. Camilo, F. Cardoso, S. Chatterjee, J. M. Cordes, F. Crawford, J. S. Deneva, R. D. Ferdman, P. C. C. Freire, J. W. T. Hessels, V. M. Kaspi, J. van Leeuwen, R. S. Lynch, A. G. Lyne, B. W. Meyers, E. Parent, C. Patel, B. B. P. Perera, S. M. Ransom, P. Scholz, I. H. Stairs, B. W. Stappers, W. W. Zhu
Disordered Systems and Neural Networks · Cross-listed from math.PR
Overlap distribution of the critical Sherrington-Kirkpatrick model
Hang Du and Brice Huang
We study the distribution of the two-replica overlap $R_{1,2}$ in the Ising and spherical Sherrington-Kirkpatrick models at the critical inverse temperature $\beta = 1$. Our main result shows that in both models, $R_{1,2}$ has scale $N^{-1/3}$, and the quenched distribution of $N^{1/3} R_{1,2}$ converges to an explicit random probability measure defined in terms of the reflected $\mathrm{Airy}_1$ point process. As a consequence, we characterize the limiting value of $N^{2/3} \mathbb{E} \langle R_{1,2}^2 \rangle$, answering a question of Talagrand \cite{talagrand2011mean2}. For the spherical SK model, we obtain the limit by representing the Gibbs measure as an anisotropic Gaussian on $\mathbb{R}^N$ conditioned to have norm $\sqrt{N}$, and then passing to the $\mathrm{Airy}_1$ scaling limit at the GOE spectral edge. For the Ising SK model, the proof is based on a sphere-to-cube comparison principle showing that the quenched distributions of $N^{1/3} R_{1,2}$ under the spherical and Ising Gibbs measures asymptotically coincide. This paper is a companion to \cite{du2026fluctuations}, where we introduced a related comparison principle to identify the limiting fluctuations of the SK free energy. Most of the arguments in this paper were generated using GPT-5.6 Pro, with the aim of exploring further consequences of the ideas developed in that work.
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Quantum Physics
Promise and Challenges of Distimation
Joshua Carlo A. Casapao, Ananda G. Maity, Naphan Benchasattabuse et al. (+4 more)
Estimating the quality of raw entangled states and distilling high-fidelity
entanglement traditionally require two separate link-layer protocols in a
quantum network stack, each consuming its own share of fragile entangled pairs. The recently introduced distimation concept merges these two protocols by directly extracting state estimation data from the classical syndromes generated during
entanglement distillation. By removing the dedicated "test-then-distill” stage, distimation lowers the number of raw entangled pairs required to operate the network, reduces latency, and streamlines the network control plane. The paradigm is especially attractive for near-term hardware platforms, where
entanglement generation remains a severe bottleneck. Alongside these promises, distimation introduces new engineering challenges, ranging from accurate local-device modeling to protocols for tracking time-varying sources. This article surveys the core principles of distimation, quantifies expected gains for realistic architectures, and outlines a research roadmap toward making distimation a standard building block in future
quantum networks.
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All authors Joshua Carlo A. Casapao, Ananda G. Maity, Naphan Benchasattabuse, Michal Hajdušek, Akihito Soeda, Rodney Van Meter, David Elkouss
Materials Science
Microscopic Origin of Spin Splitting in Altermagnetic CrSb Thin Films
Dai Mingyang, Song Hongquan, Kang Zhuo et al. (+2 more)
Altermagnets have recently emerged as promising materials for spintronic applications owing to their momentum-dependent
spin splitting. Among them, metallic CrSb is particularly attractive owing to its
giant spin splitting and high Néel temperature. However, the microscopic origin of the distinct
spin-splitting behaviors in bulk and thin-film CrSb remains unresolved. Here, we systematically investigate the electronic structures of CrSb slabs with different surface orientations using first-principles calculations. Although all considered slabs preserve
spin-group
symmetries compatible with altermagnetism, they exhibit markedly different electronic structures: the (2$\bar{1}\bar{1}$0) slab retains pronounced altermagnetic
spin splitting, whereas the (0001) and (10$\bar{1}$0) slabs display nearly
spin-degenerate bands. We demonstrate that dimensional reduction fundamentally changes the microscopic origin of altermagnetic
spin splitting. Unlike bulk CrSb, altermagnetic
spin splitting in thin films requires long-range inter-unit-
cell coplanar Cr–Sb hopping, while Sb–Sb hopping provides an additional contribution. The preservation or suppression of these hopping pathways explains the strong surface dependence of the
spin splitting. Our findings establish a microscopic mechanism for understanding altermagnetism in reduced dimensions and provide a general principle for engineering
spin splitting in low-dimensional altermagnetic materials.
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All authors Dai Mingyang, Song Hongquan, Kang Zhuo, Xu Yuanji, Tian Fuyang
Quantum Physics
DA-CASE: reusable measurements for adaptive quantum subspaces
Ginanjar Utama and Hermawan Kresno Dipojono
Quantum subspace methods are often compared by basis dimension or energyerror, although their dominant experimental costs arise from different statepreparations, measurement settings, and shot allocations. We present theDyadic Adaptive Clifford-
Algebra Subspace Eigensolver (DA-CASE), whose basisstates are virtual directions $A_i|\psi\rangle$ generated from one reference.Overlap,
Hamiltonian, and observable
matrices are reconstructed from onecached set of Pauli expectations on that reference. The method thereforetrades multiple prepared basis states for a potentially wide measurement bank.We make that trade explicit on a frozen eight-
qubit H$_4$
Hamiltonian. Twogenerator resolutions reach the same nine-dimensional subspace and the sameenergy to machine precision, while the retained bank changes from 7371 to 2240Pauli words. A reference-conditioned
symmetry test certifies the narrower spanwithout asserting that its individual Pauli words conserve the sector asabstract operators. Independently, a dyadic commuting hierarchy reduces thedeterminant bank from 913
qubit-wise-commuting settings to 64 fully commutingsettings, while exposing the added logical-CX cost. In a separate four-qubitfinite-shot diagnostic, covariance-aware allocation reduces theprojected-
matrix variance target by 68.9%. Mode-wise overlap regularizationremoves the observed catastrophic energy estimates and lowers RMSE, butdoubles the median error relative to a fixed cutoff. These are small-instanceexact and Monte Carlo results, not a hardware demonstration, scaling result,or
quantum advantage claim. The contribution is a single-referencemeasurement architecture and a resource ledger that keeps contexts, settings,shots,
circuit depth, and post-selection retries in their proper units.
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Quantum Gases
Ground-state phase diagram and route to supersolidity in a two-component extended Bose-Hubbard model
Xuexin Qiu, Ning Bian, Yang Liu et al. (+4 more)
We investigate the ground-state phase diagram of a two-component extended Bose-Hubbard model recently realized with dipolar
excitons, using the projected entangled-pair states. For the experimentally relevant parameter regime, checkerboard, Mott-insulating, superfluid, and
vacuum phases are identified. These phases exhibit orbital-selective character, wherein the two components occupy different
quantum states, but we find no evidence for a supersolid phase. The absence of supersolidity is attributed to the strongly interaction-dominated microscopic energy scales, which severely restrict the superfluid regime. Guided by the supersolid mechanism, we further explore a nearby parameter regime with enhanced hopping of one component and identify an orbital-selective supersolid phase. Further finite bond-dimension and unit-
cell analyses establish the robustness of this phase. Our results clarify the zero-temperature phase structure of the dipolar-
exciton platform and provide a possible route toward realizing supersolidity in this setting.
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All authors Xuexin Qiu, Ning Bian, Yang Liu, Saisai He, Z. Y. Xie, Hong-Gang Luo, Jize Zhao
Soft Condensed Matter
Interface dynamics in tissue invasion
Nino Despeignes, Lila Sarfati, Marc Durand et al. (+1 more)
We rely on a hydrodynamic description of living tissues to describe the interface separating two of them with distinct constitutive properties. Using the difference in their homeostatic pressures as a control parameter, we show that the interface generates an emergent capillary surface tension that depends on the hydrodynamic scale, and that makes it very stable to large wavelengths perturbations. Using the difference of active forces the two tissues experience as a control parameter, we not only find that the front propagation mechanism shifts from the pushed wave to the Burgers wave, but we also find that the emergent surface tension is not sufficient to stabilize the interface at large enough drive and low enough viscosity.
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All authors Nino Despeignes, Lila Sarfati, Marc Durand, Frédéric van Wijland
High Energy Astrophysical Phenomena
Simulation-based inference for AGN jet population modelling: Towards more robust comparisons of black hole jet speeds
Clara Lilje, James H. Matthews and Rob Fender
We present the most complete modelling of the MOJAVE 1.5 Jansky Quarter Century active
galactic nuclei (AGN) jet population, using likelihood-free simulation-based inference. Due to the complex impact of a flux-limit on observed AGN data sets, careful modelling of the parent population is required. In particular, when observing and fitting to multiple data distributions likelihoods become non-intuitive. Parameter degeneracies further complicate the problem and make it suitable for likelihood-free, simulation-based inference. This method relies on a normalising flow learning the likelihood surface or posteriors directly. We extensively validate the flow to show that previous parameter estimates for the AGN jet speed distributions underestimated parameter errors significantly and do not capture the non-gaussianity of the parameter posteriors. The new results enable a better statistical comparison to other AGN population studies, but also a more accurate comparison of supermassive black hole jets with their lower mass counterparts, X-ray binaries (XRB). We find that the AGN follow a Lorentz factor distribution of the shape $N(\Gamma) \propto \Gamma^b$ with $b= -1.32_{-0.19}^{+0.20}$. This slope is consistent with the XRB Lorentz factor distribution at $2\sigma$. Simulation-based inference as a method is generally well-suited to many astrophysical problems, and this paper shows the convenient applicability of this methodology to parent population studies of jetted AGN with multiple observables specifically.
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Instrumentation and Methods for Astrophysics
The James Webb Space Telescope Absolute Flux Calibration. VI. Near-Infrared Camera Imaging and Coronagraphy
Martha L. Boyer, Benjamin Sunnquist, Bryan Hilbert et al. (+4 more)
We present an updated flux calibration for all imaging modes of the Near-Infrared Camera on JWST that converts instrumental units to physical surface brightness units of MJy sr^-1. This calibration includes observations of 19 flux standard
stars spanning 3.5 years, with a mix of A
dwarfs,
solar analogs, and hot
stars. All 5 coronagraphic setups, all 29 filters, and both weak lenses are calibrated. This is the first on-sky calibration for the weak lenses used in Time Series observations and for secondary coronagraphic configurations (long wavelength masks paired with short wavelength filters, and vice versa). We also assess count-rate differences between subarrays and the full frame, finding differences of up to ~1%. These differences are incorporated into the calibration factors. We find that the scatter in the calibration factor is typically <2%, with about half of the filter+detector[+mask] combinations reaching <1% scatter. There are no trends with detector effects such as the count rate and well depth. Images in a handful of filters of the Large Magellanic Cloud and globular cluster 47 Tuc show that residual detector-to-detector offsets are typically small (<1%), but can be as high as 4-5%. The NIRCam detectors are found to be quite stable, with possible count-rate decreases of <0.4% per year, which is within the calibration uncertainties. These new calibration factors were incorporated into the JWST pipeline in 2026 March.
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All authors Martha L. Boyer, Benjamin Sunnquist, Bryan Hilbert, Dan Coe, Varun Bajaj, Paul Bennet, Julien Girard
High Energy Physics (Theory)
The explicit Lorentz invariant QED pair production rates from superstrings
J. X. Lu
We present a new avenue to the usual Schwinger effect via the open string pair production for a system of two Dp branes with $1 \le p \le 6$ in Type II superstrings. The two Dp are placed parallel at a separation with one of them carrying the most general constant electromagnetic background allowed for the pair production. By taking the so-called field theory limit, we obtain systematically, from the open string pair production rate, the respective explicit Lorentz invariant QED pair production rate in diverse dimensions for a pair of charged/anti-charged massive particles, which can be scalars, spinors or vectors.
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General Relativity and Quantum Cosmology
Completing the Penrose Process without a Horizon
Yang Huang, Shiyang Hu, Bin Chen et al. (+1 more)
In its standard black-hole realization, the Penrose process uses an event horizon to remove a negative-energy fragment. We show that, at the kinematic level, horizon absorption can instead be replaced by confinement within a compact ergoregion, without imposing an absorbing or reflecting inner boundary. For a broad class of regular, stationary, axisymmetric, asymptotically flat horizonless spacetimes, we prove that every smooth connected component of the spatial ergosurface is a compact
torus, independently of the field equations and matter content. Future-directed geodesics with negative Killing energy encounter a forbidden neighborhood of each such boundary component and are therefore confined. We derive an exterior no-barrier condition and identify an open set of on-shell, future-directed, four-momentum-conserving splittings producing both a confined negative-energy fragment and an amplified partner. Under equatorial reflection
symmetry, once the latter enters the exterior channel on an outward branch, it necessarily reaches infinity. A rotating
boson star explicitly realizes the complete process without a horizon.
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All authors Yang Huang, Shiyang Hu, Bin Chen, Minyong Guo
High Energy Physics (Phenomenology)
Sneutrino Tribrid Inflation in Flipped $\mathbf{SU(5)}$: Confronting ACT DR6 and Planck Observations
Farishta Israr, Mansoor Ur Rehman and Saleh O. Allehabi
We construct a realization of sneutrino tribrid inflation within the $R$-symmetric flipped $SU(5)$ grand unified theory. A vector-like pair of matter multiplets, $10_V+\overline{10}_V$, provides a $D$-flat inflaton direction along the right-handed sneutrino component, with an additional $Z_2$
symmetry forbidding a direct inflaton mass term so that the leading inflationary interaction is a non-renormalizable Kähler-driven operator. Unlike previous studies, we treat the superpotential cutoff scale $M_s$ as independent of the reduced Planck mass, $m_P$, substantially enlarging the viable parameter space. Confronting the model with the ACT DR6/Planck determination $n_s=0.9734\pm0.0034$ and the $2\sigma$ bound on the running of the spectral index, we identify broad regions of viable parameter space in which the flipped $SU(5)$
symmetry-breaking scale can approach the conventional GUT scale, $M\simeq M_{\rm GUT}$, and the tensor-to-scalar ratio can reach observable values, $r\gtrsim10^{-3}$, within reach of forthcoming CMB $B$-mode experiment such as LiteBIRD. We further study the post-inflationary dynamics, identifying the inflaton with the lightest right-handed sneutrino in a conventional type-I seesaw sector, whose out-of-
equilibrium decay generates a
lepton asymmetry that is converted into the observed
baryon asymmetry via non-thermal leptogenesis and electroweak sphalerons, for a reheating temperature consistent with both successful leptogenesis and the gravitino constraint.
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Mesoscale and Nanoscale Physics
Interaction between Rydberg Excitons in Cuprous Oxide Revealed through Resonant Second Harmonic Generation
Andreas Farenbruch, Henje Stolz, Peter Grünwald et al. (+5 more)
We report experimental and theoretical investigations of interacting
excitons of the yellow series in cuprous
oxide (Cu$_2$O) with principal
quantum numbers up to by means of second harmonic generation (SHG). Using picosecond pulsed
laser excitation up to 10 GW/cm$^2$ peak intensity we observe a pronounced change of the spectra with increasing pump
laser intensity: an energetic shift to lower absolute energies and a spectral broadening. The absolute intensities of the spectral lines scale for low powers with the square of the pump power, but saturates at higher powers. At still higher powers the SHG intensity is actually reduced. To explain these results quantitively, we developed a semi-classical theory of resonant SHG where the process of SHG is fully coherent. The
excitons are assumed to be
bosons interacting by a distance dependent potential giving rise to both the changes in spectral line shape and the saturation by a $\it{Rydberg}$ blockade. The concomitant measurement of two-
photon absorption allows to derive quantitative values for the
exciton-
exciton interaction. While the results agree in order of magnitude with those calculated by state-of-the art atomic-like van der Waals interaction theory, the scaling with principle
quantum number is quite different. As a possible screening by an electron-hole
plasma created by three-
photon absorption into blue and violet band states could be ruled out, our results point toward fundamental differences between
excitons and atoms.
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All authors Andreas Farenbruch, Henje Stolz, Peter Grünwald, Dirk Semkat, Nikita Siverin, Dmitri R. Yakovlev, Dietmar Fröhlich, Manfred Bayer
Fluid Dynamics
Deformation dynamics of Oldroyd B drop in alternating electric field
Sarika Shivaji Bangar and Gaurav Tomar
The deformation of viscoelastic drops in alternating electric fields is relevant to electrohydrodynamic applications such as microfluidics, inkjet printing, and drop manipulation. We investigate the dynamics of a neutrally buoyant Oldroyd-B drop subjected to a uniform alternating electric field using asymptotic analysis and direct numerical simulations with the open-source solver Basilisk. An analytical solution is derived for small deformation and weak elasticity for an Oldroyd-B drop suspended in an Oldroyd-B medium, with both fluids modeled as leaky dielectrics under axisymmetric Stokes flow. Depending on the conductivity and permittivity ratios, six electrohydrodynamic regions are identified, characterized by distinct deformation modes, flow directions, and nonlinear responses; while some exhibit stable spheroidal deformation, others undergo pointed-tip, multi-lobed, or oblate breakup beyond a critical electric capillary number. Across high-, intermediate-, and low-frequency regimes, the deformation oscillates at twice the applied field frequency, with its mean and amplitude governed by the field frequency and viscoelasticity. For cases that produce prolate deformation under a steady field, the drop remains prolate at high frequency, exhibits brief oblate excursions at intermediate frequency, and undergoes large-amplitude oscillations between near-spherical and highly deformed states at low frequency. The mean deformation varies monotonically or non-monotonically with $De$, depending on frequency and electrical property ratios. For cases producing oblate deformation under a steady field, the drop remains oblate at high frequency, develops dimples at intermediate frequency, and breaks up at low frequency for sufficiently large $De$ and $Ca_E$; the mean deformation increases monotonically with $De$.
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Mesoscale and Nanoscale Physics
Thermodynamic evidence for interaction-driven first-order topological quantum phase transitions
Surajit Dutta, Nadav Auerbach, Chiho Yoon et al. (+12 more)
Topological
quantum phase transitions in non interacting systems occur through continuous gap closing and reopening. In strongly interacting systems, however, competing ordered states have long been predicted to drive first order transitions, although this possibility has remained experimentally unresolved. Recent transport studies of correlated phases in charge neutral rhombohedral
graphene were interpreted as evidence for continuous topological transitions. Here, using nanoSQUID on tip magnetometry, we directly image the local orbital magnetization of a
spin orbit proximitized rhombohedral
graphene quantum anomalous
Hall (QAH) state. We provide the first real space visualization of a QAH phase with a record Chern number, reconstruct its local thermodynamic gap, and track the
evolution of its magnetization across competing correlated states. Combined with self consistent Hartree Fock calculations, these measurements show that the sequential transitions between the layer
antiferromagnetic, QAH, and layer polarized insulating states are first order, accompanied by discontinuous changes in orbital magnetization. Near the phase boundaries, we observe fluctuating
magnetic domains, providing direct microscopic evidence of phase coexistence between nearly degenerate competing ordered states. Together, these observations provide the first direct thermodynamic evidence for first order topological
quantum phase transitions and establish a microscopic framework for understanding interaction driven topological
quantum phase transitions through phase competition and coexistence.
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All authors Surajit Dutta, Nadav Auerbach, Chiho Yoon, Tonghang Han, Matan Uzan, Zhengguang Lu, Niladri-Sekhar Kander, Yaozhang Zhou, Yuri Myasoedov, Martin E. Huber, Kenji Watanabe, Takashi Taniguchi, Long Ju, Fan Zhang, Eli Zeldov
Quantum Physics
A Resource-Efficient Quantum Framework for Graph Coloring and Chromatic Number Estimation
Francesco Turro and Daniele Dragoni
Many industrial optimization tasks can be modeled as graph coloring, where adjacent vertices must have different colors. This NP-hard problem is challenging for large graphs. We present a
quantum encoding requiring
qubits that scale logarithmically with the number of colors and linearly with vertices. Using adiabatic
evolution with a novel mixer
Hamiltonian and vertex terms, we compute the chromatic number and demonstrate robustness by solving constrained truck loading problems.
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