General Relativity and Quantum Cosmology
Upwind embedded boundary SBP operators: New high order numerical schemes for arbitrarily shaped domains with Cartesian grids
Conner Dailey
Embedded boundary summation by parts (SBP) methods define finite differencing based derivative operators with the added feature that the boundary need not coincide with a grid
cell, allowing a boundary to be embedded on a regular Cartesian grid. This is achieved by the introduction of interpolation/extrapolation operators that match the accuracy of the boundary closure. These methods have been used to perform black hole excision simulations on a domain with a spherical boundary embedded in a regular Cartesian grid, demonstrating their usefulness for nonlinear problems. In this work, new operators are derived using this embedded boundary framework to increase the order of accuracy of the interior and boundary closure while minimizing the boundary error. Additionally, these novel operators improve the spectral properties on the grid by generalizing to an upwind scheme that has better dispersion relation preserving properties compared to traditional SBP schemes for wave equations. These operators are tested with the curvilinear scalar wave equation on a 3D multiblock grid with an excision sphere embedded in the center block to demonstrate the robustness and accuracy of these novel embedded operators.
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Strongly Correlated Electrons
The two-particle density matrix of a Luttinger liquid
Harini Radhakrishnan, Matthias Thamm, Hatem Barghathi et al. (+2 more)
Two-particle coherence is the first level of the reduced-density-
matrix hierarchy that contains correlations inaccessible to single-particle observables, yet analytic two-particle density
matrices are rare even in one dimension. We derive a closed, finite-size expression for the equal-time two-particle reduced density
matrix of spinless
fermions in a Tomonaga-Luttinger
liquid using constructive bosonization with an explicit ultraviolet cutoff. In addition to the familiar Luttinger parameter $K$-dependent exponent $\gamma^2=(K+K^{-1}-2)/2$ which governs the spatial decay of
matrix elements, the result exposes a second exponent, $\lambda=(K^{-1}-K)/2$, which encodes correlations between opposite chiralities and controls the off-diagonal structure. The diagonal limit of the two-particle reduced density
matrix yields density correlations and the static structure factor, while its coherences resolve algebraic $2k_F$ charge-density-wave correlations for repulsion and odd-parity p-wave pairing correlations for attraction. After fixing the cutoff from the one-particle density
matrix, the analytic result quantitatively reproduces density
matrix renormalization group calculations of the interacting J-V chain within the Luttinger
liquid regime. The result connects universal Luttinger
liquid scaling with observables in finite microscopic systems.
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All authors Harini Radhakrishnan, Matthias Thamm, Hatem Barghathi, Bernd Rosenow, Adrian Del Maestro
Quantum Physics
Sergey Bravyi, David Gosset, Yinchen Liu et al. (+1 more)
We consider a broad family of Heisenberg-type
quantum spin systems that were studied by Suzuki and Fisher in 1971. This family includes, for example, the Heisenberg antiferromagnet on any bipartite graph. The ground and Gibbs states of these models are Lee-Yang tensors with radius 1: they are associated with multilinear
polynomials that possess an extraordinary zero-freeness property inside the unit polydisk in the complex plane. For each
Hamiltonian in this family we show that the spectral gap between the first-excited and ground-state energies is lower bounded by $2\mu$, where $\mu$ is the
magnetic field along the $Z$ direction. Using this result we obtain an efficient
quantum adiabatic
algorithm for the ground energy of any model in this family. The proof is based on a new inequality that relates the spectral gap of a positive semidefinite operator to its Lee-Yang radius – a quantitative strengthening of prior work of the authors that may find applications elsewhere.
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All authors Sergey Bravyi, David Gosset, Yinchen Liu, Benjamin Wong
Computational Physics · Cross-listed from cs.ET
Unified Uncertainty Quantification Framework Bridging Noisy Quantum Backends Across Variational Quantum Algorithms and Quantum Signal Processing
Priyabrata Senapati, Vibin Abraham, Qiang Guan et al. (+1 more)
We present an uncertainty quantification (UQ) framework for application level benchmarking and characterization of noisy
quantum backends. The framework compares two workload classes under one statistical pipeline: noisy intermediate scale
quantum (NISQ) variational
quantum algorithms (VQAs) and
Quantum Singular Value Transformation (QSVT) based Green's function reconstruction. For the VQA branch, we evaluate ten
benchmark families spanning chemistry, optimization, simulation, compiling, linear solving, partial differential equations, metrology, error correction,
tomography, and channel fidelity estimation. For the QSVT branch, we reconstruct orbital resolved Green's functions and spectral peaks from a block encoded real time propagator. The workflow combines
Bayesian optimization, posterior distribution refinement, sensitivity analysis, robust parameter density estimation, backend ranking, noise correlation, and resource estimation analysis. Instead of reporting only one best parameter vector, the framework identifies robust parameter regions, residual gaps to ideal behavior, backend specific failure modes, and calibration sensitive uncertainty. The result is a common
benchmark for variational and non-variational workloads that measures how reliably each backend reaches useful task level behavior.
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All authors Priyabrata Senapati, Vibin Abraham, Qiang Guan, Bo Peng
High Energy Physics (Phenomenology)
Exotic states with charm and/or strangeness
A. Martínez Torres, Breno Agatão, Pedro Brandão et al. (+3 more)
In this talk, I will discuss the properties of several exotic states with charm and/or strangeness. These states can be interpreted either as being generated from two- or three-
hadron dynamics. In particular, I will focus on $D_1(2420)$ and some predictions of three-body states obtained from $n\bar
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All authors A. Martínez Torres, Breno Agatão, Pedro Brandão, K. P. Khemchandani, Luciano M. Abreu, E. Oset
Statistical Mechanics
Memory Retention and the Classification of Renormalization-Group Fixed Points in Self-Similar Dynamics
Ko Okumura
Universality is usually associated with the loss of information about initial conditions under repeated coarse-graining or renormalization-group (RG) transformations. We show that the unified RG framework for nonlinear partial differential equations can accommodate a broader class of asymptotic fixed points in which relevant scales remain encoded in the asymptotic state. By retaining relevant length scales within the RG description, asymptotic self-similar solutions, identified with RG fixed points, become functions of all scales that survive the RG flow. A modified density-dependent
diffusion model yields a
memory-retaining RG fixed point with scaling form {\eta}^{{\alpha}}F({\xi}/{\eta}^e̱ta}}), where {\eta} represents a surviving relevant scale, while the Barenblatt equation emerges as the special case {\eta}^{{\alpha}}F({\xi}) with e̱ta}=0. These examples suggest that asymptotic RG fixed points may be classified according to whether relevant scales survive repeated RG transformations. We refer to the fixed points retaining such information as
memory-retaining fixed points. Within this perspective, anomalous scaling can be interpreted as a manifestation of information retention. The resulting classification distinguishes fixed points according to how initial-condition information survives RG flow and remains encoded in the asymptotic fixed-point function itself. The results suggest that
memory retention constitutes an organizing principle of RG fixed points complementary to the conventional classification by universality classes. In contrast with conventional
Hamiltonian-based RG, the surviving information appears as an explicit variable of the asymptotic RG fixed-point function itself.
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Quantum Physics
Circuit complexity lower bounds for quantum spin glasses
Omar Al-Ghattas and David Gamarnik
A central question in
quantum information theory is the
circuit complexity of states arising from standard many-body models. We study this question for
quantum $p$-
spin glasses, random
Hamiltonians whose interactions act on $p$-tuples of
qubits through Pauli strings. Anschuetz, Gamarnik, and Kiani (arXiv:2404.07231) showed that the optimum energy is separated from the best energy achievable by product states. This leaves open whether shallow
circuits can close the gap, since even depth-one
circuits can generate
entanglement. We show that the
entanglement needed to close the product-state gap cannot be generated at shallow depth. When the average interaction degree grows with $n$, we prove that, for all sufficiently large fixed $p$, any
circuit preparing an $n$-
qubit state whose normalized energy is within a fixed positive constant of the optimum must have depth $\Omega_p(\log n)$. In the bounded-average-degree regime, we prove a fixed-depth obstruction: for every fixed $D$, a sufficiently large degree prefactor rules out depth-$D$ preparation of near-ground states. Both results hold uniformly over
circuits with an arbitrary number of ancilla
qubits. Our results give an obstruction in the spirit of the No Low-Energy Trivial States problem of Freedman and Hastings (arXiv:1301.1363), but for random
quantum spin glasses rather than code-based
Hamiltonians such as those of Anshu, Breuckmann, and Nirkhe (arXiv:2206.13228), whose ground states admit
polynomial-size preparation
circuits. This setting opens a probabilistic route to NLTS-like questions: we recast state-preparation lower bounds for random
quantum Hamiltonians as uniform control of Gaussian processes indexed by shallow
circuits.
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Statistical Mechanics
Long-lived memory in sliding spin chains
Charles Stahl and Ethan Lake
We study a system of two
ferromagnetic one-dimensional Ising chains coupled to a thermal bath, which are driven out of
equilibrium by being moved past one another at a constant speed. We show that even at modest speeds,
magnetic friction between the two chains significantly increases the ability of the system to order. In particular, at inverse temperature $\beta$, Ising coupling $J$, and sliding speed $v$, the dynamics retains
memory of its initial magnetization for a time that increases from $\exp(O(\beta J))$ at $v = 0$ to $\exp(O((\b J)^2v))$ when $v>v_c$, where $v_c$ is a small constant.
Magnetic friction thus provides a simple mechanism for parametrically slowing down thermalization in a one-dimensional magnet.
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Optics
Smooth-Curvature Bend Design Guided by Variational Analysis for Adiabatic Multimode Integrated Photonics
Yutong Shi, Shijin Yu, Ye Huang et al. (+2 more)
Multimode photonic integrated
circuits enable ultralow-loss on-chip optical interconnects and microwave-photonic processing, yet waveguide bends dominate both chip footprint and excess loss. A high-performance multimode waveguide bend (MWB) must transmit the working mode with low loss while suppressing intermodal coupling, forcing a trade-off among bending radius, operating bandwidth, and fabrication tolerance. Here we formulate constant-width MWB design as a
curvature-dependent variational problem. By constructing a figure of merit that incorporates higher-order-mode excitation, fundamental-mode mismatch, and sidewall field intensity, we derive a necessary condition for adiabatic optimality: the
curvature profile must approach infinite differentiability throughout the bend, including its junctions with the input and output straight waveguides. This condition explains the limitations of circular and Euler bends and motivates a smooth
polynomial curvature (SPC) family with a closed-form beta-function representation. We further introduce an optimized SPC hybrid (SPCh) bend that balances junction smoothness and the interior
curvature gradient. On the 220 nm silicon-on-
insulator platform, SPCh bends achieve a mode extinction ratio below $-37$ dB from 1500-1600 nm at an effective radius of $16\,\mu\mathrm{m}$, providing more than 22 dB stronger mode suppression than a representative Euler bend at the same radius. The simulated response remains robust to $\pm 60$ nm waveguide-width deviations. Fabricated SPCh-based microring resonators reach an intrinsic quality factor of up to $7.53 \times 10^6$ and a free spectral range of up to 100 GHz through a standard silicon foundry process. The resulting design strategy provides compact, broadband, and fabrication-tolerant multimode bends for high-density optical interconnects and microwave-photonic systems.
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All authors Yutong Shi, Shijin Yu, Ye Huang, Yuan Yu, Xinliang Zhang
Soft Condensed Matter
Structure Selection by Non-Conservative 3-Body Acoustic Interactions
Qinghao Mao and Heinrich M. Jaeger
Non-conservative multi-body interactions are typically associated with instabilities and activity in driven, field-mediated systems. Here we show that they can also promote stable static structures. Combining experiments and simulations in a minimal, acoustically levitated three-particle system, we tune the relative strength of conservative and non-conservative contributions to the force field. The conservative component favors a symmetric
equilibrium configuration, whereas the non-conservative 3-body contribution selects a flattened isosceles triangle. Our results identify non-conservative multi-body forces as a mechanism for static structure selection in driven-dissipative matter in the absence of an effective-energy landscape.
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Solar and Stellar Astrophysics
Re-evaluating solar irradiance reconstructions: No evidence for large secular trends
Theodosios Chatzistergos, Natalie A. Krivova, Mathew J. Owens et al. (+1 more)
Most current irradiance reconstructions suggest only a modest secular increase in TSI between the 1700 and 1986 activity minima ($<1$ Wm$^{-2}$). However, 2 models, the CHRONOS and Penza et al. (2024; PEA24) models, suggest substantially larger changes of 2.1-5.9 Wm$^{-2}$. Although the two models differ in their architecture, both use cosmogenic isotope records combined with
neutron monitor data to describe the long-term irradiance variability. However, cross-calibrating modulation potential reconstructions from cosmogenic isotopes against
neutron monitor data remains highly uncertain. We reassess the origin and the magnitude of the large secular trends in the CHRONOS and PEA24 models. We update the CHRONOS and PEA24 models using recent heliospheric modulation potential and open
solar flux reconstructions based on geomagnetic data and
neutron monitor measurements, which provide a more reliable connection between cosmogenic isotope and
neutron monitor records. These allow the secular component of the reconstructions to be extended consistently to the satellite era and compare the resulting TSI reconstructions with direct TSI measurements. We find that the original CHRONOS and PEA24 reconstructions substantially overestimated the secular variability in irradiance. When constrained by direct TSI measurements, CHRONOS yields a TSI increase of about 0.1-0.44 Wm$^{-2}$ between the 1700 and 1986 minima, while PEA24 returns about 0.2-0.25 Wm$^{-2}$. Our analysis indicates that the previously inferred large secular trends arose primarily from improper linking cosmogenic isotope and
neutron monitor records, together with issues in the adopted smoothing approach. The updated reconstructions presented here point toward a relatively modest secular increase in TSI since the Maunder Minimum, likely below 1 Wm$^{-2}$, consistent with the majority of current irradiance models.
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All authors Theodosios Chatzistergos, Natalie A. Krivova, Mathew J. Owens, Tatiana A. Egorova
Quantum Physics
State-independent uncertainty relations on multipartite spin $1/2$-systems
Yiling Wang, Kailash Misra and Naihuan Jing
Uncertainty relations quantify fundamental limits on simultaneous measurement of
quantum observables. While conventional formulations are state-dependent, state-independent uncertainty relations (SIURs) impose universal bounds determined solely by the algebraic structure of the operators, with applications across metrology,
quantum cryptography, and
entanglement detection. Despite extensive study, exact analytical variance-based SIURs have so far been established primarily for one- and bi-partite systems, while entropic SIURs have been extended to multipartite and
memory-assisted settings through information-theoretic constructions. In contrast, exact variance-based SIURs beyond the bipartite level have remained analytically unresolved.} Here we develop a representation-theoretic framework for multipartite SIURs in collective
spin-$\tfrac{1}{2}$ systems. Using the Clebsch–Gordan decomposition and extremal analysis of total
spin variance, we derive exact state-independent bounds up to quintipartite systems. A clear structural dichotomy emerges: odd $n$ systems exhibit strictly positive universal bounds (e.g., $\Delta^2(\mathfrak{su}_2)\!\ge\!4/11$ for $n=3$), whereas even $n$ admit vanishing variance on trivial sectors but retain positive reduced-space bounds (e.g., $\Delta^2(\mathfrak{su}_2)\!\ge\!1/8$ for $n=4$). These results establish the first unified, algebraic framework for multipartite variance-based SIURs in
qubit ensembles.
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Mathematical Physics · Cross-listed from math.DG
Lipschitz continuity of the cut time for globally hyperbolic spacetimes
Alec Metsch
We prove that, for a fixed point in a globally
hyperbolic spacetime, the focalization time is locally Lipschitz continuous on the open subset of the future causal cone where it is finite. We also show that the cut time is locally Lipschitz continuous in a neighborhood of any timelike tangent vector whose associated geodesic is defined at least up to (and including) its cut time. Furthermore, we derive quantitative estimates for the Lipschitz constant near the null cone and provide a criterion ensuring that the Lipschitz property extends to null directions. As a consequence, we show that the cut locus of a point has Hausdorff codimension at least $1$. These results extend classical Lipschitz continuity results for complete Riemannian
manifolds due to Itoh-Tanaka and Li-Nirenberg. Our approach follows the method of Itoh-Tanaka, suitably adapted to the Lorentzian setting.
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Quantum Physics
Unified monogamy and polygamy relations for multipartite systems
Yue Cao, Naihuan Jing, Kailash Misra et al. (+1 more)
For a bipartite
entanglement measure $\mathcal{E}$ that satisfies the $\gamma$th-power monogamy inequality (Eq.~\eqref{e:chap1-ineq1}), and for its assisted counterpart $\mathcal{E}_a$ that obeys the $\delta$th-power polygamy inequality (Eq.~\eqref{e:chap1-ineq2}), we introduce a unified, tunable framework indexed by a parameter $m\geq1$. Within this framework, we derive two hierarchical families of refined inequalities: a tightened $\alpha$-power monogamy relation for $\mathcal{E}$, valid for all $\alpha \geq m\gamma$; a tightened $\beta$-power polygamy relation for $\mathcal{E}_a$, applicable for $(m-1)\delta < \beta \leq m\delta$. As $m$ increases, the bounds become progressively tighter, recovering known results at $m=1$. Notably, the optimal monogamy bound emerges as a piecewise function of $\alpha$, with additional correction terms activated as $\alpha$ crosses successive integer thresholds, thereby offering a sharper characterization of
entanglement distribution. We demonstrate that our results generalize and strengthen existing monogamy and polygamy relations through analytical comparisons and numerical evaluations using concurrence and concurrence of assistance. This hierarchical, parameterized approach offers enhanced and flexible tools for applications in
quantum communication,
quantum networks, and multipartite
quantum information processing.
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All authors Yue Cao, Naihuan Jing, Kailash Misra, Yiling Wang
High Energy Astrophysical Phenomena
Black-Hole Spin Measurements from X-ray Reflection Spectroscopy: Quality Criteria and Community Recommendations
Javier A. Garcia, Riley Connors, Laura W. Brenneman et al. (+1 more)
X-ray reflection spectroscopy provides one of the most powerful electromagnetic methods for measuring the dimensionless
spin of accreting black holes. It has yielded
spin constraints for
stellar-mass black holes in X-ray binaries and supermassive black holes in active
galactic nuclei, and is central to the science goals of current and future X-ray observatories. However, the technique is subject to observational and modeling systematics, including continuum-reflection degeneracy, limited spectral coverage, unresolved distant reflection or absorption, detector effects, source variability,
accretion-state dependence, and assumptions inherent to reflection models. Motivated by discussions at the 2025 Wake Forest workshop *Recent Progress on Black Hole
Spin Measurements Across the Electromagnetic and Gravitational Spectra*, we propose a practical framework for evaluating whether published reflection-based
spin measurements should be considered robust, provisional, or not assessable from the available information. The framework is built on three principles: **detectability**, requiring an unambiguous relativistic reflection signal; **uniqueness**, requiring that the relativistic component be distinguishable from the continuum, distant reflection, absorption, and instrumental effects; and **robustness**, requiring that the inferred
spin remain stable against reasonable changes in model assumptions, data selection, and
accretion-state treatment. We translate these principles into assessment criteria, a quality-classification scheme, and a reporting checklist for future studies. Calibration of these criteria through dedicated simulations is outlined here and deferred to a companion paper. Our goal is to establish a reproducible path toward a community-maintained compilation of reliable black hole
spin measurements for the high-throughput, high-resolution era of X-ray astronomy.
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All authors Javier A. Garcia, Riley Connors, Laura W. Brenneman, James F. Steiner
Instrumentation and Methods for Astrophysics
Using Muon Rings for the Calibration of the Cherenkov Telescope Array: An Analytical Solution for the Dual-Mirror Telescope Using Vector Geometry
Markus Gaug, Víctor Giráldez-Segalàs and Fiona Redmen
The analysis of ring images produced by
muons in Imaging Atmospheric Cherenkov
Telescopes (IACTs) provides a powerful and precise method for calibrating the optical throughput of the instrument and monitoring its optical point-spread function. To date, analytical solutions have been derived for single-mirror
telescopes with reflectors assumed flat. However, a complete analytical description of the Cherenkov light produced by
muons and detected by a dual-mirror
telescope - accounting for both the secondary mirror and the camera - has remained elusive, owing to the complexity of the problem. In this work, we derive such a solution using a vector-geometry formalism supported by symbolic manipulation and Taylor expansions performed with the computer
algebra system SageMath. We validate the formalism against known analytical solutions in simpler configurations and, for more complex terms, against limiting cases exhibiting the expected physical behavior. The behavior of the full solution is illustrated visually by varying the relevant parameters. The largest effects were found in the shadowing of Cherenkov light produced by inclined
muons in dual-mirror
telescopes, particularly for the Schwarzschild-Couder
Telescope (SCT) design with baffles surrounding the secondary mirror. Deviations of up to 40% are observed relative to previously employed methods. As a by-product, we derive the first-order correction to the maximum emission height of Cherenkov
photons emitted by a
muon, arising from the
curvature of the primary mirror - an effect neglected in previous studies - as well as the impact of coma aberration on the
muon rings in single-mirror
parabolic telescopes. Our results are directly applicable to
muon-based calibration of the Cherenkov
Telescope Array Observatory (CTAO).
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High Energy Astrophysical Phenomena
CRESCENDO II: Spectral cosmic rays with improved energy losses and realistic supernova seeding
Daniel Karner, Ludwig M. Böss, Klaus Dolag et al. (+1 more)
Context. Cosmological simulation codes with subgrid models for
cosmic rays (CRs) help us better understand their impact on baryonic feedback and non-thermal radiation in
galaxies and
galaxy clusters. An accurate numerical description requires a spectrally resolved treatment of the CR population, because virtually all transport, acceleration and loss processes depend on energy. Aims. We advance the treatment of CR electrons and
protons in the on-the-fly spectral CR solver CRESCENDO in OpenGadget3. Methods. We implement several new energy loss processes for both
protons and electrons and improve the computation of their energies and pressures beyond the ultra-relativistic approximation. Moreover, we present a subgrid model for CR seeding by
supernova remnants, in which physically motivated spectra are injected at sites of ongoing
star formation. Results. We test the newly implemented loss processes and the coupling between CR injection and
star formation in idealized setups. We also highlight numerical subtleties, such as the differences arising when hadronic losses are modelled as continuous or catastrophic process, and the advantages of using a flexible spectral cut-off and abandoning the ultra-relativistic approximation. Furthermore, we show that using analytical approximations to compute energy fluxes can cause the slope reconstruction to fail. Conclusions. Future applications of our spectral
cosmic-ray model in large-scale, full-physics cosmological simulations will represent an important step towards building a robust and observationally verifiable link between the microphysical and macrophysical aspects of the CR component in the modern paradigm of
galaxy evolution.
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All authors Daniel Karner, Ludwig M. Böss, Klaus Dolag, Ildar Khabibullin
Mathematical Physics · Cross-listed from math.CO
Measures and generalizations of dual Littlewood identities
Zhongren Cai, Bin Jiang, Naihuan Jing et al. (+2 more)
We introduce three families of vectors $|\underline{\lambda}^{so}\rangle$, $|\underline{\lambda}^{sp}\rangle$ and $|\underline{\lambda}^{o}\rangle$ parametrized by partitions in the Fock space by using products of adjoint vertex operators. We show that the quotient space of the dual
vacuum vector is spanned by the partition vectors indexed by a special family of partitions. The partition-indexed vectors also help us to derive the dual Littlewood identities of types B, C, and D in a new manner associated to the special family of partitions. As an application, we obtain a new free fermionic construction to show that the measures related to dual Littlewood identities introduced by Rains \cite[Section 7]{Rai2000} and Betea \cite[Section 3]{Be2020} are determinantal with repect to some explicit correlation kernels. Furthermore we establish a number of generalized Littlewood identities summed over certain restricted partitions by computing the inner products with elements indexed by one-column partitions {or generalized partitions $(0^m)$} in the complete dual Fock space. {In particular, for each positive integer $n$, we obtain generalized Littlewood identities for $(-n)$-asymmetric partitions. We show that these generalized Littlewood identities contain several well-known Littlewood-type identities as special cases. Consequently we also give a new proof of the generalized Littlewood identity \cite[(5.25)]{LSV2008} for Lie superalgebras. } %We also produce infinite generalized Littlewood identities by calculating the inner products between these elements and some elements indexed by one-column partitions in the complete dual Fock space.
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All authors Zhongren Cai, Bin Jiang, Naihuan Jing, Zhijun Li, Qianyi Ye
Chaotic Dynamics · Cross-listed from q-bio.PE
Infectious Disease Induces Emergent Oscillations, Extinction and Changes in Community Persistence in a Food Chain
Hooman Saveh and Fakhteh Ghanbarnejad
Food webs have been extensively studied from both ecological and mathematical aspects. However, most of the models studied in this area do not capture the effects of infectious diseases simultaneously. Recently, the idea of including an infectious disease in a food web model has been investigated. We study and simulate a small food chain consisting of only prey, predators, and apex predators governed by the generalized Lotka-Volterra equations, and we implement the Susceptible-Infected-Recovered (SIR) model on only one of the species at a time in the food chain. To study the effects of an infectious disease on the food chain, we introduce a new parameter that increases the predation rate by a factor of $w$ and decreases the hunting rate by a factor of $1/w$ for infected species. When the infectious disease is present in predators, we observe that predators do not become extinct under any set of parameters; however, an oscillation in their population size occurs under some circumstances, which we do not observe in ordinary SIR or the generalized Lotka-Volterra equations alone. When an infectious disease is present in apex predators, oscillations in the population size do not happen; but if the set of parameters is in a specific range the apex predators may become extinct. Furthermore, the chance of survival of the community, known as community persistence, increases for the predators and decreases for the apex predators.
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Astrophysics of Galaxies
The chemodynamical signature of coherent metal-poor inflow and enriched recycled accretion in the cool circumgalactic medium
Glenn G. Kacprzak, Jerrard Doran, Sameer et al. (+7 more)
The azimuthal and kinematic structure of the CGM is often interpreted as planar
accretion and bipolar
outflows, yet direct
metallicity evidence for this picture remains ambiguous. We combine cloud-by-cloud ionisation modelling with
galaxy rotation kinematics for 21
galaxies from the Multiphase
Galaxy Halos Survey to investigate how
metallicity depends on azimuthal angle and angular momentum. We find that low-ionisation clouds kinematically consistent with disk rotation have ~0.5 dex lower
metallicity near the projected major axis ($\Phi<30^\circ$) than at larger azimuthal angles. Major-axis clouds also exhibit higher N(HI), higher density, and reduced non-thermal line broadening compared to clouds at larger azimuthal angles. In contrast, the higher-ionisation phase shows no significant
metallicity dependence on azimuthal angle and has lower column densities, lower densities, higher temperatures, and broader line widths than the co-rotating major-axis low-ionisation clouds. These combined
metallicity–kinematic–ionisation signatures are consistent with dynamically cold, metal-poor inflow along the disk plane and enriched, more turbulent gas at larger azimuthal angles that likely traces angular-momentum-supported recycled
accretion, embedded within a dynamically complex warmer phase. These results show that
metallicity and angular momentum are jointly imprinted by the
baryon cycle and are both required to uncover the physical origins of CGM gas.
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All authors Glenn G. Kacprzak, Jerrard Doran, Sameer, James Farrington, Jane C. Charlton, Nikole M. Nielsen, Kaustubh R. Gupta, Christopher W. Churchill, Tania M. Barone, Antonia Fernández-Figueroa
High Energy Astrophysical Phenomena
Multiwavelength study of non-thermal emission in the Swift J1834.9-0846/W41 region
Manoel F. Sousa, Rita C. Dos Anjos and Vitor de Souza
We investigate the origin of non-thermal emission from the Swift J1834-0846/W41 region by modeling its broadband spectral energy distribution from
radio to TeV energies within leptonic and lepto-hadronic frameworks using Markov Chain Monte Carlo sampling. Motivated by morphological studies of HESS J1834-087 suggesting a two-component TeV structure, we explore a single extended source scenario and a configuration comprising a central point-like component embedded within extended emission. Purely leptonic models are disfavored in both scenarios by unrealistically low
magnetic field strengths, whereas lepto-hadronic solutions yield field intensities and non-thermal energy budgets consistent with an evolved
supernova remnant undergoing efficient
cosmic-ray acceleration. In the two-component scenario, hadronic interactions dominate the extended TeV emission from W41, while the central excess is well described by a leptonic magnetar wind nebula powered by Swift J1834-0846, implying a short initial
spin period of $P_0 \lesssim 0.2$ s. Simulated observations with the Cherenkov
Telescope Array Observatory show that 30 h exposures will discriminate between the two morphological configurations and extend spectral measurements beyond $\sim$10 TeV.
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Astrophysics of Galaxies
VENUS: an ultra-faint galaxy hosting the metal-poor type II supernova at $z=5.13$ Witnessing the initial metal enrichment with extremely frequent core-collapse supernovae?
Yoshihisa Asada, Seiji Fujimoto, Joseph F. V. Allingham et al. (+50 more)
We present the first characterization of the host
galaxy of a recently discovered type IIP SN at $z=5.13$ (SN Eos). SN Eos and its host
galaxy are gravitationally lensed and multiply imaged. The total magnification $\mu\sim53$ enables spatially resolving the system, allowing us to localize the core-collapse
supernova (CCSN) position and to characterize its local environment within an early
galaxy. Our observation reveals that the host is an ultra-faint ($M_{\rm UV}=-14.4\pm0.3$ mag) Lyman-$\alpha$ emitter with a very high equivalent width. The host
galaxy also shows very weak [O iii]4959,5007 lines despite an H$\alpha$ line detection ([O iii]5007/H$\beta <0.7$ with case B recombination). Assuming that the weak [O iii] is due to low gas-phase
metallicity given the low-
metallicity of SN Eos itself, SN Eos plausibly marks the formation and explosion of a metal-poor
star in an extremely metal-poor environment ($<1\ \%\ Z_\odot$), facilitating the initial stages of the chemical enrichment of the host. Finding the CCSN in such an ultra-faint
galaxy at $z=5.13$ also indicates that the SN rate could be considerably higher in high-$z$, metal-poor environments, potentially implying e.g., a $Z$-dependent IMF, $Z$-dependent massive
star explodability, or runaway
stellar collisions in dense
star clusters. Without
lensing, only SN Eos would be detectable and the host would be below the detection limit in any NIRCam surveys ever performed. The Eos host
galaxy can thus be representative of the origin of hostless
supernovae frequently found in JWST blank field surveys.
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All authors Yoshihisa Asada, Seiji Fujimoto, Joseph F. V. Allingham, David A. Coulter, Conor Larison, Matthew R. Siebert, Gabriel Brammer, Dan Coe, Pratika Dayal, Qinyue Fei, Lukas J. Furtak, Vasily Kokorev, Keiichi Maeda, Richard Pan, Johan Richard, Fengwu Sun, Abdurro'uf, Jacqueline Antwi-Danso, Franz E. Bauer, Marusa Bradac, Larry D. Bradley, Volker Bromm, John Chisholm, Christopher J. Conselice, Christa DeCoursey, Anderas L. Faisst, Brenda Frye, Mauro Gonzalez-Otero, Yuichi Harikane, Tiger Y. Y. Hsiao, Kohei Inayoshi, Yolanda Jimenez-Teja, Anton M. Koekemoer, Kotaro Kohno, Paulo A. A. Lopes, Ray A. Lucas, Georgios E. Magdis, Vladan Markov, Nicholas Martis, Jorryt Matthee, Minami Nakane, Rohan P. Naidu, Gael Noirot, Masami Ouchi, Armin Rest, Massimo Ricotti, Louis-Gregory Strolger, Raffaella Schneider, Francesco Valentino, Eros Vanzella, Hayley Williams, Rogier A. Windhorst, Adi Zitrin
Accelerator Physics
Foundation of Three-Dimensional Spiral Beam Injection Using Canonical Angular Momentum and Symplectic Eigen-Modes
Hiromi Iinuma
Aiming for high injection efficiency in three-dimensional spiral injection, the underlying physical principles governing beam formation and matching should be systematically organized within a unified canonical framework. However, a general theoretical framework explaining why particular beam distributions become naturally matched has not yet been established. In this work, a canonical description of three-dimensional spiral injection is developed based on the eigensystem of the
symplectic covariance
matrix $J\Sigma$. Canonical modal families are introduced to represent the underlying beam structure, and statistically broadened beam distributions are synthesized around the corresponding modal skeletons while preserving their canonical
topology. Unlike conventional beam-matching methods based on Twiss parameters or eigen-emittance analysis, the proposed framework employs canonical
symplectic modes as design variables for beam-family synthesis. It provides a unified description of beam geometry and canonical angular momentum in terms of canonical
symplectic modes, and enables beam distributions to be interpreted in terms of their dominant modal structures. Beyond providing a canonical design representation of three-dimensional spiral injection, this approach establishes a direct connection between canonical beam dynamics and experimentally realizable injection beams, thereby providing a theoretical basis for systematic beam synthesis and injection-beam design. The framework further enables the systematic representation, synthesis, and evaluation of statistical distributions of spiral-injection beams in canonical modal space.
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High Energy Physics (Theory)
Lectures on Open Systems and Cosmology
Enrico Pajer
Open systems are ubiquitous in physics. Many realistic systems interact, at least weakly, with environmental degrees of freedom that may be too numerous, too complicated, inaccessible, or unknown. When only a subset of degrees of freedom is observed, its reduced dynamics can differ qualitatively from that of a closed system, displaying dissipation, noise, decoherence,
memory effects, or loss of information into unobserved sectors. When the microscopic description is also unknown, one is led to an open effective description, in which the relevant degrees of freedom are treated systematically while the environment and the microscopics are parametrized rather than solved for explicitly. This perspective is especially important in
gravity and cosmology. The main open problems of cosmology, including inflation, dark matter, and dark energy, involve spacetime-filling sectors whose microscopic nature is unknown and whose observed effects are primarily gravitational. At the same time, gravitational systems often lack a preferred notion of conserved energy because they are time dependent, and naturally display out-of-
equilibrium dynamics. These lecture notes introduce the operator formalism and the Schwinger-Keldysh path-integral as tools to study open systems, with emphasis on open effective field theories and inflation. They are aimed at master students, PhD students, and researchers approaching these topics for the first time.
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Cosmology and Nongalactic Astrophysics
The plethora of diffuse emission in Abell 2034 as revealed by MeerKAT polarization observations
A. Bonafede, M. Balboni, G.W. Pratt et al. (+15 more)
We present MeerKAT observations of the
galaxy cluster Abell 2034, a massive (M_500=5.21 10^14
solar masses) nearby cluster in a merging state. Previous observations at 144 MHz have shown that the cluster exhibits a plethora of diffuse emission, with multiple diffuse sources of uncertain classification because of the lack of spectral and polarimetric observations. MeerKAT multi-frequency observations, centered at 816 MHz and 1.28 GHz, together with archival low-frequency LOFAR observations at 144 MHz have allowed us to shed light on the properties of these sources. The polarization properties and spectral index information let us conclude that the cluster hosts one
radio relic, a source with a very steep spectrum, previously classified as candidate relic, and filaments of very steep emission around the tailed
radio galaxies identified at low frequencies. The presence of a
radio halo is confirmed, and its spectrum shows hints for
curvature between 144 MHz ad 1.28 GHz. The polarimetric data in the L-band, together with the model of the gas density derived from X-ray observations are used to constrain the
magnetic field in the intracluster medium. We assume a radially symmetric
magnetic field model, whose strength declines with the cluster gas density as B(r) ~ n_e(r)^0.5, and normalize its strength within R_500. We find that B_500=1 muG best explains the Faraday depth properties of the cluster, though the detection of sources close to the cluster center would be crucial to discriminate among different values. We conclude that the cluster Abell 2034 shows diffuse emission with complex morphologies that do not follow the historical categories of
halos and relics. Deep multi-frequency and polarimetric observations are fundamental to understand their origin.
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All authors A. Bonafede, M. Balboni, G.W. Pratt, I. Bartalucci, L. Rudnick, C. J. Riseley, C. Stuardi, B. Hugo, G. Bernardi, M. Brüggen, G. Brunetti, R. Cassano, F. De Gasperin, F. Gastaldello, K. Knowles, F. Loi, T. Shimwell, R. J. van Weeren
Quantum Physics
Collapse and Inversion of the Josephson Potential in a Strongly Driven Superconducting Circuit
Sercan Deve, Marius Villiers, Marijn A. Morssink et al. (+2 more)
Superconducting
circuits embedding Josephson junctions leverage microwave drives for control and measurement of
quantum states. Although increasing the drive power is desirable for improving the efficiency of these operations, it eventually triggers unwanted transitions to uncontrolled states. While careful choice of
circuit symmetries and parameters can mitigate these effects, the presence of spurious
circuit modes spoils the resilience to high power. In this work, we engineer a transmon-resonator system free of any detrimental unwanted transitions. This resilience enables us to access drive powers at which we uncover a remarkable physical phenomenon: the collapse and inversion of the Josephson potential. Through spectroscopy and readout experiments, we confirm that the driven potential goes to zero and inverts as the power increases. The inversion corresponds to the dynamical stabilization of the transmon at its unstable
equilibrium point, directly analogous to an inverted pendulum. This result reveals a new limitation of strongly driven superconducting
circuits beyond drive-induced transitions. In addition, the dynamical renormalization of the Josephson potential opens up novel avenues for the control of superconducting
circuits, and the autonomous stabilization of noise-resilient
quantum states.
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All authors Sercan Deve, Marius Villiers, Marijn A. Morssink, Robin C. Dekker, Gary A. Steele
Mathematical Physics
Quantum Markov Chains for an Asymmetric Mixed Ising-XY Model on a Cayley Tree
Farrukh Mukhamedov
We study a mixed
quantum Ising-$XY$ model on the semi-infinite rooted Cayley tree of order two. For every vertex $u$, the edge $\langle u,(u,1)\rangle$ carries an $XY$ interaction and the edge $\langle u,(u,2)\rangle$ carries an Ising interaction. Using the compatibility criterion for tree-indexed
quantum Markov chains and consistently working with the normalized trace, we derive the translation-invariant boundary equation and compute explicitly the associated local transfer operator, namely the one-step partial-trace map which propagates successor boundary data to the parent vertex. We prove that the boundary equation has a unique positive translation-invariant solution for all $J_I,J_{XY}\in\mathbb R$ and $\beta>0$. Hence the model admits a unique translation-invariant
quantum Markov chain generated by a positive translation-invariant boundary condition. We also show that the reduced boundary-law dynamics, i.e. the induced finite-dimensional recursion for the boundary-law parameters, has no admissible periodic points of period greater than one and compute the local two-site
entanglement on the natural three-site cluster of the tree.
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Mathematical Physics · Cross-listed from math.CO
Universal Asymptotics and Exact Enumeration of Eulerian Maps
Ahmad Barhoumi, Roozbeh Gharakhloo and Nathan Hayford
We calculate the asymptotics of the number of connected, labeled, genus $g$ Eulerian maps with an arbitrary degree sequence, in the limit as the total number of vertices tends to infinity. This asymptotic is universal, in the sense that the leading-order term depends on only three map characteristics, regardless of the choice of the degree sequence. The constant factor in this formula is related to the Painlevé I equation. Our methods combine for the first time the analysis of the recurrence coefficients associated to a particular family of orthogonal
polynomials, and the theory of analytic combinatorics of several variables. We also derive an exact formula for the number of connected, labeled, genus $1$ Eulerian maps. These are the first results on this kind of enumeration problem for $g\geq 1$, non-regular (mixed-valence) maps.
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High Energy Astrophysical Phenomena
X-Ray Timing Properties of the Black Hole Candidate IGR J17091-3624 During the 2022 Outburst Onset with AstroSat
Sree Bhattacherjee and Biplob Sarkar
We present the
evolution of rapid X-ray timing variability in the black hole X-ray binary IGR J17091-3624 during the initial phase of its 2022 outburst using a ~3-day-long AstroSat observation. Utilizing the high time-resolution capability of the Large Area X-ray Proportional Counter, we perform a comprehensive study of the
evolution of Type-C quasi-periodic oscillations (QPOs) throughout the observation. The QPO centroid frequency evolves from 3.30 to 7.78 Hz, accompanied by the broad-band noise characteristics. We further investigate the energy dependence of the fractional rms variability and time lags, finding that the fractional rms exhibits a positive energy dependence, with its amplitude evolving throughout the observation, while the time lags exhibit the soft-lag behavior and evolve with QPO frequency. These findings provide important insights into the
evolution of geometry of the inner
accretion flow during the onset phase of the 2022 outburst of IGR J17091-3624.
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High Energy Physics (Theory)
The variational approach to infrared divergencies: Applications to black hole action integrals and holographic Wilson loops
M. Arroyo, D. Arteaga, M. Bañados et al. (+1 more)
Renormalizing the on-shell action variation offers two important advantages over renormalizing the action itself. First, the variation of the action has a universal form in which the bulk contribution vanishes identically. As a result, the renormalization problem is automatically localized at the boundary; no bulk subtractions are required. Second, the variation of the action admits a natural interpretation as a 1-form on functional space. The distinction between exact and non-exact 1-forms provides a clear renormalization prescription. We apply these ideas to the computation of on-shell black hole actions. After presenting the general
algorithm, we discuss some examples, including Kerr-Newman, Kerr-Newman-AdS, Taub-NUT, Taub-Bolt, and STU black holes. We also apply the same techniques to the computation of
holographic Wilson loops. All results agree with standard results, in particular with
holographic renormalization.
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All authors M. Arroyo, D. Arteaga, M. Bañados, A. Faraggi