General Physics
Study of the dark energy models in f(Q, Lm) gravity in different formalisms
Vidhi Tayal, Shaily, Vimal Kumar et al. (+2 more)
We study the late time cosmological
evolution of the Universe in the framework of a flat Friedmann Lemaitre Robertson-Walker spacetime in f(Q,Lm)
gravity. The
cosmic dynamics of the Friedmann equations are discussed using various equation of state (EoS) parameters like Chevallier Polarski Linder (CPL), Jassal Bagla Padmanabhan (JBP), Barboza Alcaniz (BA), and Logarithmic (LOG). We use joint observational
datasets of Hubble (OHD), DES five year Type Ia
supernovae (DES 5YR), and the
Baryon Acoustic Oscillation (BAO) measurements to obtain the best fit values of model parameters, which show good agreement with current observations. These models exhibit a smooth transition from early deceleration to late time acceleration. The equation of state parameter displays quintessence like behaviour over a wide
redshift range and gradually converges its behaviour from quintessence-like to phantom-like behaviour as z tends to -1, except in the BA case. Furthermore, we investigate the physical characteristics of the model in order to assess its physical viability. We also analyse the energy conditions and examine the stability of the proposed model.
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All authors Vidhi Tayal, Shaily, Vimal Kumar, J. K. Singh, Anirudh Pradhan
Mathematical Physics · Cross-listed from q-bio.CB
A coupled geometric surface and surface reaction-diffusion framework for modelling nuclear mechanics during confined cell migration
Francesca Ballatore, Silvia Comunian, Anotida Madzvamuse et al. (+2 more)
Confined
cell migration is governed by
nuclear and cellular deformation. In this work, we formulate a two-dimensional mathematical framework in which the
cell and
nuclear membranes are represented as evolving closed surfaces governed by force-balance laws incorporating surface tension, bending elasticity, and external mechanical interactions.
Nuclear mechanics depends on several factors, including chromatin organization and compaction, which are regulated by epigenetic modifications. Molecular regulation at the
nuclear periphery is described by a surface reaction-
diffusion system posed on the evolving
nuclear surface. We apply this coupled framework to an experimentally characterized lung cancer
cell model in which the balance between the enzymes SETDB1 and SUV39H1 regulates the peripheral deposition of H3K9me3. Using experimentally measured mechanical parameters, we represent control (Ctrl) and SETDB1 knockout (SETDB1 KO) conditions, which display distinct H3K9me3 distributions, especially at the
nuclear periphery. Numerical solutions obtained using the evolving surface finite element method qualitatively reproduce the changes in
nuclear mechanics as well as part of the experimentally observed increase in the entry time in SETDB1 KO
cells. The model therefore reproduces the direction of the experimental observations, while the residual difference between simulated and measured entry times indicates that the cellular response is multifactorial.
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All authors Francesca Ballatore, Silvia Comunian, Anotida Madzvamuse, Slimane Ait-Si-Ali, Rachele Allena
Quantum Physics
Quantum gates from the middle convolution of twisted Burau representations
Haru Negami
We study braid representations obtained from character-twisted Burau inputs by the Katz-Long-Moody (KLM) construction, which corresponds to multiplicative middle convolution for KZ-type equations. For $n\ge2$, let $q=e^{2\pi ia}$, $\tau=e^{2\pi ic}$, where $a,c>0$ and $nc+(n+1)a<1$. Known form and signature results give a positive-definite invariant form for $\lambda=e^{2\pi il}$, $0<l<1-nc-(n+1)a$. For fixed input,
unitary realizations are unique up to simultaneous
unitary conjugation. We address two questions. First, we determine spectra and invariant summands of the $M=n(n+1)$-dimensional output. The generator spectrum recovers $(q,\tau)$. The output decomposes into two trivial and two reduced Burau summands, and an $n(n-1)$-dimensional summand isomorphic to Long's reduced construction, generically irreducible for $n=3,4$. If $a$ or $c$ is irrational, every generator is non-Clifford in every finite-dimensional Weyl-Heisenberg frame; if $1,a,c$ are linearly independent over $\mathbb{Q}$, every generator is entangling for every nontrivial bipartition. The full braid image is not projectively dense. For general positive-definite
unitary inputs, irreducibility of the full braid output at a nonexceptional parameter forces the free-group input operators to commute. Second, we construct one orthonormal basis giving each generator one block of size $2(n+1)$, $n-2$ blocks of size two, and identity elsewhere. Each generator is a product of $2n$ rank-one phase reflections and, in a fixed binary encoding, an $O(M)$-length word in one-
qubit unitaries and CNOTs, without auxiliary
qubits and including direction preparation and its inverse. We give finite-alphabet approximation, conditioning and error bounds, and a matched-resource comparison with a
Quantum Shannon reference compiler. The gate bound is exponential in the encoded
qubit count and excludes classical preprocessing.
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Quantum Physics
Nonlinear collective-spin dynamics for quantum-enhanced sensing in solid-state platforms
Le Bin Ho
Collective
spin systems in solid-state materials are promising platforms for
quantum-enhanced sensing. In systems such as nitrogen-vacancy centers in diamond, donor
spins in silicon, and
magnetic materials, interactions among many
spins can generate collective
quantum correlations that improve measurement precision beyond the standard
quantum limit. This tutorial develops an intuitive, materials-oriented framework for understanding these effects through nonlinear collective-
spin dynamics. We show how nonlinear interactions reshape collective
spin states in phase space, redistribute
quantum fluctuations, and generate metrologically useful states such as
spin-squeezed and entangled states. We then connect these ideal collective dynamics to microscopic interactions and realistic solid-state systems, discussing how interaction strength, disorder, decoherence, and experimental control affect sensing performance. Different platforms and experiments are compared to highlight key material properties, advantages, and limitations. The tutorial focuses on a materials-oriented understanding of nonlinear collective-
spin sensing, rather than a comprehensive comparison of experimental platforms or a practical guide to sensing experiments.
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Fluid Dynamics
Airfoil2Vec: Spectral Geometry-Conditioned Neural Surrogate Models for Airfoil Aerodynamics and a Downforce-Generating CFD Dataset
Haitz Sáez de Ocáriz Borde, Flavio Savarino, Andrei Cristian Popescu et al. (+3 more)
We introduce a
dataset of approximately 10,000 Reynolds-Averaged Navier-Stokes (RANS) simulations of steady, incompressible, two-dimensional subsonic flow around downforce-generating NACA 4-digit airfoils, targeting aerodynamic regimes relevant to automotive and motorsport applications (openly available on https://huggingface.co/
datasets/ratiolabs/downforce-airfoils). Using this resource, we study geometry-conditioned neural surrogates for fast flow prediction, comparing neural fields with neural ODEs, MLPs with graph-based models, and several spectral geometry-conditioning methods. We further propose Airfoil2Vec, an airfoil-specific spectral geometry encoder that combines the joint contour spectrum with separate spectral representations of camber and thickness, for predicting continuous pressure and velocity fields. We evaluate generalization through angle-of-attack interpolation, interpolation and extrapolation to unseen NACA 4-digit geometries, and generalization to unseen non-NACA airfoils. The resulting surrogate accurately captures aerodynamic quantities and qualitative flow features while providing orders-of-magnitude speedups over conventional computational fluid dynamics.
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All authors Haitz Sáez de Ocáriz Borde, Flavio Savarino, Andrei Cristian Popescu, Pietro Innocenzi, Pantelis Papageorgiou, Xerxes Xian Chong
General Relativity and Quantum Cosmology
Five-dimensional thick branes in the scalar representation of $f(Q,B)$ gravity
F. C. E. Lima, F. M. Belchior and C. A. S. Almeida
One examines a codimension-one thick braneworld in the scalar representation of $f(Q,B)$
gravity, where $Q$ is the nonmetricity scalar, and $B$ is the boundary term satisfying $R=Q-B$. We write the gravitational sector in terms of two auxiliary scalar fields, $\varphi=f_Q$ and $\psi=f_B$, and an interaction potential $U(\varphi,\psi)$ obtained by a Legendre transformation from the $f(Q,B)$ function. Working in the coincident gauge and assuming a five-dimensional warped geometry with four-dimensional Poincaré
symmetry, we derive the complete set of brane equations sourced by a canonical bulk scalar field. To accomplish our purpose, we address two models of smooth asymptotically AdS thick brane with localized scalar profiles. Furthermore, we also analyze tensor perturbations and demonstrate the localization and stability of the massless graviton.
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Instrumentation and Detectors
Development of LGAD Sensor Technology on 12 inch Wafers for 3D Integration with advanced CMOS processes
Ron Lipton, Julie Segal, Angela Kok et al. (+10 more)
We report on the design, simulation, and initial testing of Low Gain Avalanche Diode (LGAD) sensors fabricated in 65 nm CMOS technology on 12 inch wafers. These sensors were developed as part of a project to demonstrate full wafer to wafer hybrid bonding of sensors and 28 nm Readout Integrated
Circuits (ROICs). The sensor submission and test included standard (reach-through) LGADs, AC coupled LGADs, and Deep Junction LGADs as well as various test structures.
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All authors Ron Lipton, Julie Segal, Angela Kok, Troy England, Artur Apresyan, Davide Braga, Farah Fahim, Shuoxing Wu, Christopher Kenney, Bojan Markovic, Ariel Gustavo Schwartzman, Lorenzo Rota, Arthur Carpenter
Instrumentation and Detectors
WLCG Mini-Capability Challenge: Host Tuning to Im- prove WAN Data Transfers
Andrew Malone Melo, Carlos Fernando Gamboa, Diego Devila Foyo et al. (+8 more)
High-throughput data movement is a defining requirement of the WLCG computing model, yet end-to-end performance is often constrained less by the network backbone than by host-level configuration. We present the results of a WLCG mini-capability challenge focused on host optimization at ATLAS and CMS sites (FNAL, UCSD, UNL, BNL, AGLT2, MWT2, and Vanderbilt), using EL8/9 hosts with 25\,Gbps or higher NICs. NET2 participated in a subsequent trans-Atlantic test. The methodology combines ESnet Fasterdata guidance with the OSG-hosted fasterdata-tuning.sh framework, applying TCP, queue, offload, and ring-buffer tuning with save and restore support for safe baseline comparisons. Results show that tuning benefit depends critically on the local bottleneck. Where DTNs and storage were both capable (UNL), FTS throughput rose from 60 to 90\,Gbps. Where storage was the binding constraint (UCSD), iperf3 throughput improved from 20 to 90\,Gbps while FTS was unchanged. Where the NIC was the binding constraint (Vanderbilt, 25\,G NIC), the tuning profile actively reduced throughput, motivating a review of per-site applicability. The challenge also surfaced and resolved a dCache proxying misconfiguration at AGLT2, demonstrating that mini-challenges serve a diagnostic function beyond raw performance measurement.
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All authors Andrew Malone Melo, Carlos Fernando Gamboa, Diego Devila Foyo, Eduardo Bach, Eli Dart, Shawn McKee, Garhan Attebury, Philippe Laurens, Wendy Wu, Syed Asif Shaw, Hiro Ito
Classical Physics
The Myth of Hamel's Paradox
Robert Singer
Substituting a velocity constraint into the kinetic energy before forming Lagrange's equations yields, in general, incorrect equations of motion. Recent literature calls this failure "Hamel's paradox," a term introduced in 2010. We show that there is no paradox. The inadmissibility of the substitution was recognized in the 1890s; C. Neumann (1899) named the operation the illegitimate form of the kinetic energy, and Hadamard (1895), Chaplygin (1897), Appell (1899) and Hamel (1904) established its limits of validity. Hamel's textbook of 1949, the nominal source of the paradox, states the prohibition and uses Neumann's term; the result remained in print in the specialist literature and in
geometric mechanics. The modern debate cites none of this record; we collect it from the primary sources and measure the debate's claims against it. A
geometric analysis identifies the substituted function as the restriction of the mass metric to the constraint distribution. If the distribution is integrable, the restriction is the induced metric of an integral
manifold, and the substitution is legitimate. If not, the correctly embedded Boltzmann–Hamel equations differ from those of the restricted energy by a single residue, $\mathrm{Res}_\alpha=c^{s}_{\alpha\beta} \omega^\beta P_s$, relative to the complement of the constraint distribution that the shortcut selects. The residue vanishes exactly when the symmetric part of its coefficient vanishes. The two classical admissibility mechanisms, decoupling of the mass metric and vanishing bracket components, are sufficient for this and, for a single constraint, also necessary; for several constraints they are not, which corrects a necessity claim in Hamel's paper of 1904.
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Instrumentation and Detectors
Quantitative characterization of superconducting qubits as particle detectors
Francesco De Dominicis, Raja Yasir Mehmood Khan, Dounia L Helis et al. (+22 more)
Ionizing radiation is a major source of correlated errors in superconducting
quantum processors, yet the mechanisms responsible for the
qubit response to particle interactions remain only partially understood. In this work, we operate superconducting
qubits as particle detectors while simultaneously monitoring the deposited energy with an independent
semiconductor cryogenic sensor. This complementary measurement provides an absolute determination of the particle interaction rate in the chip, enabling the first direct measurement of the detection efficiency of superconducting
qubits exposed to environmental radiation. We measure individual
qubit detection efficiencies of about 30-40$\%$, increasing to approximately 50$\%$ when combining the response of two
qubits. Under the conservative assumption that the efficiency loss is entirely determined by a finite detection threshold, we derive an upper limit on the effective energy threshold of the detector of $70\pm20~\mathrm{(stat)}\pm30~\mathrm{(syst)}~\mathrm{keV}$. Measurements with radioactive sources producing different deposited-energy spectra further show that the detection efficiency decreases for lower-energy interactions. We further investigate the origin of the
qubit response by injecting controlled thermal pulses with a resistive heater. Although these pulses deposit energies comparable to those released by particle interactions, they do not reproduce the radiation-induced signatures, demonstrating that the
qubit response to radiation cannot be explained by a transient increase in substrate temperature alone. Our results establish an experimental framework for quantitatively connecting particle energy deposition to radiation-induced responses in superconducting
quantum circuits.
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All authors Francesco De Dominicis, Raja Yasir Mehmood Khan, Dounia L Helis, Ambra Mariani, Letizia Tirabasso, Alberto Ressa, Mustafa Bal, Fabio Bellini, Camilla Bonomo, Nicola Casali, Gianluigi Catelani, Ivan Colantoni, Francesco Crisa, Angelo Cruciani, Sabrina Garattoni, Luca Gironi, Andrea Melchiorre, Lorenzo Pagnanini, Valerio Pettinacci, Stefano Pirro, Andrei Puiu, Tanay Roy, Shaojiang Zhu, Anna Grassellino, Laura Cardani
Applied Physics
A reduced-order analysis for multi-reflection-driven laser absorptance in vaporization-induced cavities
Haolin Liu, Haoran Shi, Xuzhe Zeng et al. (+4 more)
Multiple internal reflections enhance
laser absorption in vaporization-induced cavities, but connecting ray histories, cavity geometry, and absorptance typically requires full ray tracing. We develop a reduced-order framework based on Beer-Lambert-type attenuation governed by an effective per-reflection optical depth (EPROD). A power-weighted formulation defines an absorptance-equivalent interaction count under constant effective single-interaction absorptance, while a cumulant expansion separates the EPROD-independent mean interaction count from ray-path heterogeneity corrections. Across nine simulation groups spanning three
alloys and three spot diameters, the mean interaction count follows a unit-intercept linear depth relation with R-squared values of 0.7824-0.9843. Its slope varies by only 3.4%-6.3% across
alloys at fixed spot diameter and decreases with increasing spot diameter. Fixing this slope from ray statistics yields an absorptance-depth model with one fitted parameter and a median prediction error (MAPE) of 2.61%. An independent synchronized Ti-64 experiment yields model parameters within approximately 2.4% of corresponding simulation values. This framework separates
geometric interaction accumulation from optical attenuation, enabling efficient energy-coupling prediction and absorptance-based keyhole characterization.
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All authors Haolin Liu, Haoran Shi, Xuzhe Zeng, Brian J. Simonds, Wenda Tan, Anthony D. Rollett, Levent Burak Kara
Cosmology and Nongalactic Astrophysics
Galaxy and Halo Assembly Bias in Alternative Dark Matter Models
Yikun Wang, Idit Zehavi, Sergio Contreras et al. (+6 more)
The clustering of dark matter
halos depends not only on
halo mass but also on secondary
halo properties, a phenomenon known as
halo assembly bias. Coupled with variations in
halo occupation, this dependence impacts
galaxy clustering, an effect termed
galaxy assembly bias. While previous studies have found only weak cosmological dependence of assembly bias within the $\Lambda$CDM framework, its sensitivity to the underlying dark matter physics remains largely unexplored. We use the matched dark-matter-only and hydrodynamical simulations from the AIDA-TNG suite to measure assembly bias across four dark matter models: cold dark matter, warm dark matter, and self-interacting dark matter with constant cross-sections and velocity-dependent cross-sections. We find that at z = 0,
halo assembly bias is nearly identical across the four models for concentration-selected
halos, as is the concentration dependence of the
halo occupation distribution. The resulting
galaxy assembly bias signals likewise show only weak model dependence. For
stellar-mass-selected
galaxy samples with $n = 0.0586 h^{3} Mpc^{-3}$ at z = 0, the velocity-dependent self-interacting dark matter scenario exhibits the largest deviation from the fiducial cold dark matter model: its assembly bias contribution to
galaxy clustering is enhanced by up to $\sim 6\%$, corresponding to a $\sim 3\%$ difference in the assembly bias amplitude. Although statistically distinguishable, this difference is small and unlikely to be detected in current analyses. The weak model dependence persists across different
galaxy number densities and
redshifts. Overall, within the TNG
galaxy-formation framework, these results indicate that assembly bias is largely insensitive to the dark matter models explored here, providing a robust baseline for future studies of the
galaxy-
halo connection in alternative dark matter scenarios.
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All authors Yikun Wang, Idit Zehavi, Sergio Contreras, Jonás Chaves-Montero, Giulia Despali, Carlo Giocoli, Lauro Moscardini, Massimiliano Romanello, Mark Vogelsberger
Statistical Mechanics
Odd stochastic density functional theory
Yael Avni, Michel Fruchart, David Martin et al. (+2 more)
Stochastic density functional theory (SDFT) provides a powerful framework for studying the dynamics of many-body systems both in and out of
equilibrium. In its standard form, it can be viewed as a density-based formulation of coupled Langevin equations with white noise. Here, we extend SDFT to a class of systems, ranging from magnetized electrolytes to
chiral active matter, that possess a
chiral overdamped limit in which a relaxation timescale and an oscillation period are simultaneously taken to zero. We derive this formulation, which we dub “odd SDFT", by taking the overdamped limit of a fluctuating hydrodynamic description of underdamped particles subject to a Lorentz force. We establish the validity and utility of the resulting framework by calculating the collective mobility tensor of interacting particles using both direct linear response and a Green-Kubo relation. We then apply the theory to the
Hall conductivity of electrolytes in
magnetic fields. Going beyond mean-field theory and using two distinct Green-Kubo relations, we derive the full conductivity tensor, extending the relaxation part of the Debye-Hückel-Onsager theory to the case of finite
magnetic fields.
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All authors Yael Avni, Michel Fruchart, David Martin, Tali Khain, Vincenzo Vitelli
Chemical Physics
Reinforcement learning amortizes transition-state physics into one-step flow models
Yunyang Li, Zechang Sun, Kuang Yu et al. (+3 more)
Transition-state searches remain a major bottleneck in reaction discovery, as identifying valid saddle-point structures requires numerous expensive
quantum-chemical calculations. Generative models can reduce this burden by proposing candidates from reactant and product geometries, but supervised training on geometries alone does not enforce the physical conditions required of a transition state, while enforcing them during sampling is costly. We introduce Trèfle, a one-step flow model that amortizes physics-guided generation into training: a mean-flow objective replaces multi-step sampling, a low-cost surrogate replaces density functional theory (DFT) reward evaluations, and reinforcement-learning post-training with rewards that enforce those conditions replaces inference-time guidance. Trèfle generates accurate transition states at $30\times$ the throughput of multi-step baselines. It transfers few-shot to ten unseen transition metals and generalizes zero-shot to molecules far larger than any in training. With DFT refinement and reaction-path validation, Trèfle-seeded searches recover all 13 unseen $\gamma$-ketohydroperoxide channels, while post-training raises per-attempt recovery from 28% to 50% across 85 unseen bimolecular channels. Trèfle thus provides fast, reliable seeds for automated reaction discovery.
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All authors Yunyang Li, Zechang Sun, Kuang Yu, Wen Yan, Mark Gerstein, Hung Q. Pham
High Energy Physics (Theory)
A backreacted bouncing geodesic in 2D
Gauri Batra, Adam Levine and Stephen H. Shenker
In holography, analytically continued finite temperature correlation functions $G(t)$ exhibit signatures of the black hole singularity. These take the form of singularities at certain values of $t$ whose bulk origin is a null geodesic worldline "bouncing off" the black hole singularity. We study certain
quantum corrections to this effect in 2D dilaton
gravity that are captured by gravitational backreaction of the worldline onto the black hole geometry. These corrections smooth out the bouncing geodesic singularities. By following the backreacted geodesic saddle in a steepest descent analysis we find instead that the black hole singularity physics gets encoded in a subtle way involving a Stokes phenomenon near the coincident point singularity of $G(t)$ at $t=0$ (and its thermal image). We point out a parallel between the structure of Stokes lines uncovered in this analysis and the structure present in the analysis of forbidden singularities in large $c$ 2D conformal blocks. Finally we make some preliminary remarks about the significance of
quantum corrections in these models beyond backreaction.
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Plasma Physics
Controlling $\gamma$-photon production with additively manufactured microstructured targets
Joshua Luoma, Andreas Kemp, Thomas G. White et al. (+3 more)
Nonlinear inverse Compton scattering (NICS) in high-density targets offers a promising route for generating high flux, broadband sources of MeV $\gamma$-
photons which are important for applications like radiography, photonuclear physics, and pair production. Microstructured targets enable control over the NICS process to help shape the
photon energy, angular distribution, and total yield. This work presents particle-in-
cell (PIC) simulations exploring target microstructures compatible with two-
photon polymerization (TPP) additive manufacturing, which is a promising technique that allows high-volume and reproducible printing of sub-wavelength features as small as 200 nm. We investigate how microstructures influence NICS radiation and merge simulation analysis with simple analytical models that guide target design. These results establish pathways to optimize targets for low-divergence, high-energy
photon beams with 2.0$\cdot$10$^{8}$
photons/J exceeding 100 MeV and targets for high yields delivering upwards of 2.0$\cdot$10$^{11}$
photons/J above 1 MeV in the multi-PW regime.
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All authors Joshua Luoma, Andreas Kemp, Thomas G. White, Dean Rusby, Hui Chen, Gennady Shvets
Mathematical Physics · Cross-listed from math.PR
From Ehrenfest to Heisenberg scales: a hierarchy of mixing times for a phase-randomized quantum baker walk
Amir Sepehri
The
quantum baker map is a standard model of
quantum chaos, but rigorous analysis of how it spreads random perturbations remains difficult. Following the repeated “baker plus refreshed diagonal perturbation” architecture of Schack and Caves, we study a tractable strong-noise model based on the Balazs–Voros quantization: at each time step, its
unitary propagator is followed by a diagonal
unitary whose entries are independent and uniform on the unit circle. The resulting random propagator is a structured random walk on $\U(N)$, $N=2^k$. We quantify how quickly the baker dynamics spreads this basis-local randomness at three levels: ensemble means, two-copy statistics, and the full law of the accumulated propagator. The walk becomes an exact
unitary $1$-design at time $k+1$, while its fixed-accuracy $2$-design mixing time is $\Theta(\log N)$. Thus the induced state ensembles reproduce Haar means and two-copy statistics on the Ehrenfest scale. The full law mixes much more slowly. A phase-adapted path coupling gives normalized Wasserstein mixing in $O_\varepsilon(N)$ steps, whereas metric-
entropy and Haar small-ball estimates give an $\Omega_\varepsilon(N/\log N)$ lower bound and asymptotically maximal distance at every $t=o(N/\log N)$. The law remains singular with respect to Haar measure for every $t<N$. The moment results and the Wasserstein upper bound are driven by the unistochastic Markov kernel associated with $B_N$, an affine dyadic chain whose nonconstant
Fourier modes vanish exactly after $k$ steps. The resulting hierarchy separates Ehrenfest-scale randomization of state ensembles from near-Heisenberg-scale exploration of the full
unitary group.
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High Energy Physics (Theory)
Puxin Lin and Gary Shiu
We derive the
axion Weak
Gravity Conjecture (aWGC) from the nonperturbative fragmentation of Euclidean wormholes into charged defects. Requiring fragmentation to lower the Euclidean action fixes the
axion action-to-charge bound and its order-one coefficient. Without additional scalars, this coefficient coincides with that of the Imaginary Distance Bound (IDB), while additional scalars strengthen the bound. The aWGC in the presence of multiple axio-dilaton pairs is discussed, leading to
geometric representations.
Axions satisfying the aWGC render the corresponding wormholes unstable, potentially suppressing their proliferation and resolving associated factorization problems.
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Mesoscale and Nanoscale Physics
A.J. Balseyro Sebastian, Keisuke Ohashi and Muneto Nitta
We study charged
soliton branches in quasi-one-dimensional
chiral magnetic systems with Dzyaloshinskii–Moriya (DM) interaction, easy-axis anisotropy, and Zeeman coupling. The same static
magnetic functional is equipped with two different dynamical completions: an
antiferromagnetic model with second-order time derivatives and a
ferromagnetic model with Berry-phase dynamics. On the helical branch selected by the static DM interaction, the problem reduces to an analytically tractable one-dimensional system for the polar angle of the order parameter. We derive the existence conditions for polar Q-balls from the
curvature of the reduced effective potential and the presence of a nonzero turning point. In the
antiferromagnetic case, the allowed frequency window is symmetric and can be completely closed by the combined effect of the DM coupling and the Zeeman field. At zero Zeeman field, the same reduction also supports
antiferromagnetic Q-kinks, for which we obtain explicit profiles, charges, energies, and reduced-sector fission criteria. In the
ferromagnetic case, the Berry phase makes the rotation frequency act as a shifted Zeeman field. As a result, north- and south-pole charged droplets are selected by opposite signs of the shifted rotation. We also show that a formal pole-to-pole solution of the
ferromagnetic mechanical problem does not generally correspond to a finite-energy
magnetic soliton, because the Berry term does not renormalize the physical
Hamiltonian. These results clarify how charged-
soliton mechanisms depend on the underlying
magnetic dynamics, even when the static
chiral energy is the same.
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High Energy Physics (Phenomenology)
The era of charmed resonance searches at the LHC
Daniel Whiteson
The LHC dijet program has searched extensively for resonances decaying to inclusive jets and, more recently, to bottom-
quark jets, where the sensitivity enhancement from suppression of the background outweighs the loss of signal efficiency in bottom-
quark tagging. However, no dedicated search for dijet resonances containing charm-tagged jets has been performed. We study the charm-tagging performance required to make such searches competitive with the inclusive dijet search. Using the ATLAS 13 TeV dijet mass spectrum with 139 fb$^{-1}$, we predict the expected charm-tagged spectra from simulated jet-
flavor fractions and parameterized charm-, bottom-, and light-jet tagging efficiencies, and estimate the sensitivity of a profile-likelihood search in exclusive one- and two-tag categories. At the loosest working point of the current tagger, charm-tagged searches improve the expected sensitivity to a resonance decaying to two charm
quarks across the full resonance mass range considered, although the quantitative sensitivity depends on the poorly constrained high-$\pt$ behavior of charm-tagging efficiencies and on the simulated heavy-
flavor composition of the dijet background. These results provide performance targets for charm taggers and motivate the development of dedicated charm-tagged dijet resonance searches at the LHC.
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General Relativity and Quantum Cosmology
Relational Frame Equivalence and Exact Cosmology in Brans–Dicke Theory
Yaser Tavakoli
We apply the canonical clock-sector framework developed in Ref.~\cite{Tavakoli:2026coc} to spatially flat FLRW cosmology in Brans–Dicke theory. The aim is to obtain an explicit cosmological realization of the frame-adapted relational dynamics and to determine the corresponding cosmological observables in closed form. Starting from the previously developed full ADM theory and restricting it to the homogeneous sector, we obtain the canonical clock momentum as $P_{\Phi}=p_{\phi}-ap_a/2\phi$. This identification allows the Jordan and Einstein-frame reduced systems to be represented on a common canonical phase space. We then consider a quadratic Jordan-frame potential for which the Einstein-frame potential is constant. The resulting relational FLRW system is exactly integrable. The complete trajectory can be expressed in terms of a single parameter $u$, yielding closed-form expressions for the scale factor, the
cosmic-time Hubble rate, the Hubble slow-roll parameter, the number of e-folds, and the scalar equation-of-state parameter. In particular, the exact solution provides an explicit inflationary regime that begins at $u=\operatorname{arctanh}(1/\sqrt{3})$ and transitions toward an asymptotic de Sitter regime. We finally compare the exact solution with direct numerical integration in the adapted Jordan and Einstein descriptions, and with the naively reduced Jordan system based on the unshifted scalar momentum. The numerical results reproduce the exact trajectory and illustrate how the different reduced canonical representations are related by the clock-dependent transformation implied by the canonical clock-sector construction. The analysis provides an exactly solvable laboratory for relational frame equivalence in scalar–tensor cosmology and gives explicit cosmological observables that can be used in extensions to more general potentials and scalar–tensor models.
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Astrophysics of Galaxies
The AURORA Survey: Determining the Production Mechanism for OI $\mathbf{\lambda 8449}$ Emission in Star-forming Galaxies at Cosmic Noon
Leonardo Clarke, Alice E. Shapley, Zhiwei Shao et al. (+11 more)
We analyze deep JWST/NIRSpec observations of 58
star-forming
galaxies at $1.3< z <4.8$ in the AURORA survey to investigate the origin of the permitted OI $\lambda 8449$ emission feature. Based on the detection of OI $\lambda 8449$ in a stack of objects with non-detections, we infer that this feature is ubiquitous among
star-forming
galaxies at $\sim$0.5% the strength of H$\alpha$. We additionally compare our results with measurements of this line in local HII regions from the CHAOS survey and
star-forming
galaxies at $z<0.1619$ in the DESI survey, finding a similar strength of OI $\lambda 8449$ relative to H$\alpha$ in these objects. We evaluate four production mechanisms: recombination, collisional excitation, Ly$\beta$ fluorescence, and
stellar continuum fluorescence. Of these mechanisms,
stellar continuum fluorescence (rather than Ly$\beta$ fluorescence) provides the most compelling explanation for the OI $\lambda 8449$ emission based on the additional detection of the near-infrared OI $\lambda 11290$ and OI $\lambda 13168$ emission lines. Adopting physical conditions derived from a stacked composite spectrum, we make predictions for the contribution of the other mechanisms to OI $\lambda 8449$, determining that recombination, collisional excitation, and Ly$\beta$ fluorescence contribute negligibly to this feature. While a simple HII region model using Cloudy reproduces the average observed OI $\lambda 8449$/H$\alpha$ ratios in the AURORA sample, future works focused on refining model density profiles will be a valuable step in better explaining the near-infrared OI emission-line strengths.
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All authors Leonardo Clarke, Alice E. Shapley, Zhiwei Shao, Massimo Pascale, Ryan L. Sanders, Naveen A. Reddy, Tucker Jones, Harley Katz, Natalie Lam, Shreya Karthikeyan, Callum T. Donnan, Natascha M. Förster Schreiber, Anthony J. Pahl, Danielle A. Berg
Earth and Planetary Astrophysics
Investigating potential causes for high inferred intrinsic temperatures of warm transiting Neptune and Sub-Neptune planets
Saugata Barat, Jean-Michel Désert, Allona Vazan et al. (+7 more)
Atmospheric characterization of a warm 10-30 Myr old sub-Neptune progenitor (V1298 Tau b) and a $\sim$3.4 Gyr old warm super-Neptune (WASP-107b) using JWST have revealed extremely low methane abundance. Atmospheric forward models find higher than expected inferred intrinsic temperatures (450~K and 500~K) — inconsistent with theoretical
planet formation and core-envelope
evolution predictions (70K and 150K respectively) assuming a convective interior. We explore three hypotheses to reconcile the high intrinsic temperatures with evolutionary models —
tidal heating, silicate rainout and heat trapping due to deep cloud condensation.
Tidal heating requires high planetary obliquity ($\gtrsim70^{\circ}$) and low reduced
tidal quality factor ($\sim$100) for V1298 Tau b, implying an extremely short obliquity damping timescale ($<$10$^{4}$ years). Although high obliquity may be maintained by
spin–orbit resonant locking, it requires fine-tuning and is therefore unlikely. Silicate rainout can increase the temperature in the deep atmosphere of the young V1298 Tau b (0.1-1 bar) by $\sim$700K, without requiring extremely high intrinsic temperature, but is unlikely to explain WASP-107b, as silicate rainout timescales are expected to be much shorter than its age. Including cloud condensation in self-consistent atmospheric models reduces the inferred intrinsic temperature for V1298 Tau b from 500K to 300K, still exceeding the core-envelope prediction (150K). Future measurements of thermal emission from young transiting
planets such as V1298 Tau b, combined with methane abundances as a function of age, will be needed to distinguish between these scenarios.
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All authors Saugata Barat, Jean-Michel Désert, Allona Vazan, Ritika Sethi, Sagnick Mukherjee, Sarah Millholland, Jonathan J. Fortney, William Misener, Hilke E. Schlichting, Sara Seager
Chemical Physics
Bridging Molecular Scales with Implicit Score Matching for Bottom-Up Coarse Graining
Patrick G. Sahrmann, Nicholas Lubbers, Benjamin T. Nebgen et al. (+4 more)
Molecular dynamics simulations provide a computational microscope for atomic scale processes but remain restricted to relatively small spatial and temporal scales. Coarse-grained models extend their reach by representing groups of atoms as effective interaction sites. The number of particles is systematically reduced by
embedding the collective behavior of groups of atoms into coarse-grained sites governed by effective potentials. However, constructing accurate, highly coarsened potentials, even with the assistance of modern machine-learning methods, is a grand challenge because coarse grained forces depend on a statistical distribution of composite atomic configurations making direct calculation computationally prohibitive. Here, we introduce an alternative framework based on implicit score matching that directly avoids the need for explicit coarse-grained forces. This approach both substantially reduces the training data required relative to conventional force-matching methods and enables high-fidelity models in which each coarse-grained site represents hundreds to thousands of atoms. We demonstrate the method's versatility and effectiveness across a diverse range of chemical systems and phenomena, developing bottom-up, machine-learned models. These enable efficient modeling at micrometer and millimeter length scales, while retaining significant amounts of the atomic scale fidelity. These results establish implicit score matching as a practical route towards chemically accurate simulations that bridge molecular and mesoscopic scales.
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All authors Patrick G. Sahrmann, Nicholas Lubbers, Benjamin T. Nebgen, Emily Shinkle, Sergei Tretiak, Kipton Barros, Brenden W. Hamilton
Cosmology and Nongalactic Astrophysics
CMB Data Analysis in the example of the POLARBEAR experiment and the LiteBIRD experiment
Kolen Cheung
In this dissertation, I briefly go through my subject areas — from Astrophysics, Cosmology, to
Cosmic Microwave Background (CMB) radiation; and Data Science & High-Performance Computing. I go through the beginning of the Universe briefly in part I and introduce the Physics of the CMB in part II. Then I move on to how it can be observed experimentally, mathematically, and computationally in part III. In parts IV to VI, I write about 2 specific CMB experiments — POLARBEAR & LiteBIRD, together with my research involved in them. In part V, original research on a measurement of the CMB $B$-mode at sub-degree scales is presented using the 3rd-5th seasons of POLARBEAR observations. This demonstrates the capability of a single medium aperture
telescope with a Continuously Rotating Half-Wave Plate (CRHWP) to target both the low-$\ell$ and high-$\ell$ $B$-mode science at $50 \leq \ell \leq 3000$. In part VI, the effect of detector crosstalk systematics on the CMB power-spectra is studied in detail in the example of the LiteBIRD experiment. An analytical, map-domain solution is developed, a computational simulation method is implemented, and the two predictions are compared using the LiteBIRD experiment design specification. The general agreement of the two shows that the analytical model well describes the LiteBIRD experiment, and can be used to calculate the systematic effects without performing time-consuming time-domain simulations with a high degree of accuracy. This can be used to forecast the amount of crosstalk systematics and to develop mitigation strategies. A mitigation strategy is presented, which is a hardware-based mitigation method that minimizes the crosstalk systematic effects in the 2pt power-spectra.
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Quantum Physics
Nonstabilizerness of the entangling layer in quantum circuit Born machines
Marcin Płodzień
The entangling layer of a
quantum circuit Born machine can supply both
entanglement and nonstabilizerness. In this work we show that the entangling layer can be a Clifford
circuit, which supplies no nonstabilizerness. We use an architecture in which a fixed, non-trainable entangler is reused in every layer and only single-
qubit rotations are optimized. There, a Clifford entangler reaches the same Kullback–Leibler divergence as a near-Haar one at sufficient
circuit depth, and entanglers spanning zero to Haar-typical nonstabilizerness reach the same loss, up to a small offset for a free-
fermion matchgate entangler. A doping control that raises the entangler's nonstabilizerness while leaving the entangling power of every gate unchanged leaves the loss flat. With a Clifford entangler the nonstabilizerness of the trained state comes entirely from the rotations, which take the trained
circuit outside the stabilizer formalism. We also show that, among all pure states whose Born distribution is a given target, the one whose amplitudes are the positive square roots of the probabilities has the smallest stabilizer Rényi
entropy, so this minimum can be computed without training.
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Quantum Physics
Robust Entanglement Witnessing via Dense Network Coding with Graph States
Brian Doolittle and Ian George
Practical tests for witnessing
entanglement in the presence of noise are needed to verify and apply
entanglement-based applications in real-world communication networks.
Quantum dense network coding is a communication protocol that uses an entangled state preparation together with
quantum communication to halve the amount of communication needed to evaluate certain bijective functions in networks having multiple senders and one receiver. In this work, we consider a dense network coding protocol that uses graph state
entanglement to implement a family of affine transformations, we derive a bound on the success probability that can be achieved by classical networks, and we show that the noise robustness exponentially amplifies with the number of senders. We apply our results in a semi-device-independent protocol for robustly estimating the effective visibility of graph states and measurement bases. Overall, our approaches are robust to noise, can support the usage of uncharacterized state preparations or measurements, and can be applied to any graph state.
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Instrumentation and Methods for Astrophysics
An Analytic Error-Budget Model for the Habitable Worlds Observatory Coronagraph: From Optical Disturbances to Flux-Ratio Noise
Slava G. Turyshev
A coronagraph stability allocation must protect a
planet measurement, not merely satisfy a contrast target. Residual starlight both generates
photon noise and interferes with small field perturbations, coupling optical stability to detection reliability. We develop a modular analytic model for the Habitable Worlds Observatory (HWO), using a reduced two-roll angular-differential-imaging realization of its OS-1 scenario. Complex-field sensitivities, wavefront sensing/control, finite observing windows, polarization, detector calibration are propagated to flux-ratio noise (FRN) and detection probabilities. Joint-visit Gaussian quadratic moments retain differential bias, cross covariance; spatial overlap/field phase determine which disturbances resemble a
planet. A 6-m, 500-nm
benchmark shows why the science test must precede category allocation. For a 115.46-parts-per-trillion (ppt) quadrature
planet, 30,000 independent Gaussian search statistics, and a $10^{-3}$ family-wise false-alarm objective, 20-ppt FRN gives 64.55% conditional detection power; 99% requires 14.94 ppt.
Photon and calibration noise exhaust the optical remainder at 8.11 pc in 100 h under the fixed response, so tighter stability alone cannot restore feasibility. An unrecognized 1% high-variance component carrying twenty percent of the variance tightens the modal allowance by a factor of 2.88; an ideal, exactly known state label reduces that penalty to 1.29 under equal conditional false-alarm limits and the same average-power objective. Thus, requirements depend on both the optical response and the information retained by the observing protocol. The framework identifies when suppression, stability, calibration, or state monitoring addresses the limiting mechanism. Numerical tolerances are controlled model results; flight allocation requires architecture-specific responses and calibrated disturbance state-estimation laws.
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Instrumentation and Methods for Astrophysics
A Delayed Rejection Reversible Jump Markov Chain Monte Carlo Method for Multi-Resolution Maps of the Stochastic Gravitational Wave Background with Pulsar Timing Array Data
Taha T. Moursy and Nihan S. Pol
Pulsar timing array anisotropy analyses often use a naive counting argument to set resolutions of inferred maps of the
stochastic gravitational wave background (GWB). We present a data-driven method in the form of a delayed rejection reversible jump sampler tailored to multi-resolution pixel decompositions of the angular power density of the GWB. We also consider a rapid, frequentist alternative based on information criteria statistics. We verify our methods with a series of injection-and-recovery simulations, finding that the standard counting argument would lead to drastic overfitting of the data and that our data-driven methods reduce the number of parameters in the models by one to three orders of magnitude yet can achieve higher resolution than the standard counting argument when justified by the data. We make our sampler and frequentist method implementation available on GitHub.
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