Astrophysics of Galaxies
Detectable subhalo impacts in Milky Way streams
Junyang Lu, Elias Bernreuther, Tongyan Lin et al. (+3 more)
Dark matter subhalos leave gravitational imprints in the
stellar streams of the Milky Way. Observing individual strong impacts of subhalos offers a compelling way to constrain and discover potentially dark subhalos down to $10^6 M_\odot$, allowing for new tests of the particle physics properties of dark matter. We develop a pipeline and statistical framework to forecast the expected number of detectable subhalo impacts on
stellar streams, based on morphological and kinematic data from surveys such as LSST and Via. Starting from a catalog of confirmed
stellar streams, we focus our efforts on 14 promising streams that are relatively well-modeled with a particle spray
algorithm. Our criteria for a detectable impact is a deviation at 95% CL from the best-fit
polynomial proxy model for the stream, which accounts for stream modeling uncertainties and regulates the effect of distant impacts that are degenerate with these uncertainties. Among the 14 streams studied, we find that 5 streams have an expected number of detectable impacts greater than 0.2. With LSST and Via data, the stream Jet has $5.15^{+1.10}_{-0.95}$ expected detectable impacts, followed by Orphan-Chenab ($1.40^{+0.62}_{-0.47}$), ATLAS-Aliqa Uma ($1.25^{+0.60}_{-0.44}$), GD-1 ($0.55^{+0.43}_{-0.28}$), and Palomar 5 ($0.40^{+0.39}_{-0.23}$), where error bars are the 95% containment on the Poisson mean. These values rely on the assumed subhalo population, which can give a factor of few systematic uncertainty in the predictions. We also consider effects of different particle dark matter models on the number of impacts, finding a suppression by a factor of $\sim 4$ for warm dark matter and fuzzy dark matter models at their current mass bounds and an $O(1)$ enhancement for a toy model of self-interacting dark matter.
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All authors Junyang Lu, Elias Bernreuther, Tongyan Lin, Vincent S. H. Lee, Ana Bonaca, Ethan O. Nadler
Statistical Mechanics
Quantum Rényi-Jarzynski Equality
Benjamin Bobell, Mert Okyay and Rahul Nandkishore
The Jarzynski equality provides a strict link between nonequilibrium work and
equilibrium free energy changes. Its typical
quantum formulations, however, rely on measurement protocols that destroy coherence. In this Letter, we use the resource-theoretic approach to derive a non-destructive
quantum Jarzynski equality conditioned on the outcomes of an arbitrary bath observable. This yields the Rényi-Jarzynski equality, which quantifies a finite bath's drift from
equilibrium under a non-adiabatic drive via the Rényi $k$-divergence. We further demonstrate that the Rényi-Jarzynski equality provides a tunable cost function for
quantum optimal control problems where minimizing bath drift is desired, such as state preparation and gate design, enabling the minimization of cross-talk in finite
quantum systems. Our toy model exhibits a transition between competing minima for some critical value of $k$, illustrating how the Rényi order tunes sensitivity to different regions of a bath distribution. Strikingly, when drive parameters vary across bath energy levels, minimizing bath drift requires generating system-bath
entanglement.
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High Energy Physics (Phenomenology)
Solar Constraints on Heavy Neutral Leptons with $\nu_\tau$ Mixing
Vedran Brdar, Samiur R. Mir and Xun-Jie Xu
The mixing of heavy neutral
leptons (HNLs) with tau
neutrinos remains largely unconstrained compared to their mixing with electron and
muon neutrinos. In this work, we investigate the potential of
solar neutrinos to improve constraints on HNL-$\nu_\tau$ mixing in the MeV mass range. Due to
neutrino oscillations, the Sun is a copious source of
neutrinos of all
flavors, and the partial conversion of electron
neutrinos into
muon and tau
neutrinos occurs already during their propagation through the
solar interior. Tau
neutrinos can produce HNLs through scattering with
protons in the Sun, provided nonzero HNL-$\nu_\tau$ mixing is present. The HNLs escape the Sun and subsequently decay through the same interaction. For $\mathcal{O}(10)$ MeV HNL masses, the dominant visible decay yields electrons and positrons that can be detected by space-based
solar observatories. Using data from the
Solar and Heliospheric Observatory (SOHO), we search for such signals and derive constraints on the squared HNL-$\nu_\tau$ mixing
matrix element, $|U_{\tau N}|^2$, reaching below the $10^{-2}$ level for HNL masses of $\sim 5$ MeV. These constraints improve upon existing terrestrial limits in this mass range by more than an order of magnitude.
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Quantum Physics
Simulating Black Hole Thermality and Interior Scrambling on a Superconducting Quantum Processor
Ryan Smith, Ewan Forbes, Iason A. Sofos et al. (+2 more)
We implement a
chiral spin-chain black hole simulator on IBM superconducting
quantum hardware and probe, within a common microscopic framework, both semiclassical horizon physics and interacting
quantum scrambling. We first measure the dispersion relation across the exterior, horizon and over-tilted interior regimes, reproducing the predicted
evolution of the effective light-cone structure. To probe Hawking thermality, we prepare a localised excitation inside the horizon and monitor its density response at an exterior site, observing the predicted inverse relation between the peak arrival time and the surface
gravity, thereby establishing a calibrated dynamical
estimator of the Hawking temperature. Beyond the semiclassical regime, we continuously tune the interactions and distinguish non-exponential operator spreading in the free-
fermion limit from Lyapunov-like OTOC decay in the strongly interacting
chiral regime. These measurements use observable-specific Floquet
circuits derived from the same parent
chiral model, including its mean-field and coordinate-equivalent XY descriptions, to reduce
circuit depth while preserving the physics relevant to each probe. Our results provide a unified programmable platform for studying horizon geometry, Hawking thermality and interacting scrambling on
quantum hardware.
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All authors Ryan Smith, Ewan Forbes, Iason A. Sofos, Andrew Hallam, Jiannis K. Pachos
High Energy Physics (Phenomenology)
NAE, Statistically
Ranit Das, Jonathan Ostertag-Henning, Tilman Plehn et al. (+1 more)
Searches for new physics using neural anomaly scores have transformative potential, but suffer from a lack of statistical interpretability. The normalized autoencoder (NAE) provides a probabilistic interpretation of the standard bottleneck architecture, tying the anomaly score to a learned likelihood. We validate this relation for a toy model, test it for jets using a dual-NAE setup, and show how a
Bayesian NAE learns this likelihood with an uncertainty.
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All authors Ranit Das, Jonathan Ostertag-Henning, Tilman Plehn, Lorenz Vogel
High Energy Physics (Phenomenology)
Universal Two-Loop Current–Current Renormalization of Four-Fermion Operators
Jason Aebischer, Sudeepan Datta, Pol Morell et al. (+2 more)
The complete one- and two-loop gauge and scalar current–current contributions to the running of arbitrary dimension-six four-
fermion operators are reported. The results are obtained in a basis-independent and renormalization-scheme-agnostic fashion and are valid for arbitrary gauge groups. The complete gauge and scalar contributions, including the genuine one- and two-loop poles, counterterm insertions, wave-function renormalization, finite evanescent insertions, diagram multiplicities, and the associated color, charge and Yukawa factors are provided for the most general renormalizable Lagrangian with gauge and scalar interactions. The results enable the derivation of leading- and next-to-leading-order current–current anomalous-dimension
matrices for arbitrary Effective Field Theories (EFTs) and constitute a significant step toward the complete two-loop renormalization of general EFTs.
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All authors Jason Aebischer, Sudeepan Datta, Pol Morell, Marko Pesut, Javier Virto
Quantum Physics
Thermal Throttling of Quantum State Transfer
Twesh Upadhyaya, T. C. Mooney, Yifan Hong et al. (+1 more)
Quantum state transfer on
qubit lattices is a crucial step in a panoply of
quantum information processing tasks. Understanding its fundamental limits in the presence of practical imperfections remains a pressing open question. In particular, it is unclear how thermal noise in the intermediate ancilla sites impedes transfer. In this work, we derive tight lower bounds on the necessary growth of commutator norms to achieve approximate state transfer. Specializing to 1D power-law systems with thermal ancilla states, we demonstrate that state transfer runtimes depend sensitively on the scaling of temperature with system size, improving logarithmic bounds to algebraic ones. Our work extends previous results on exact state transfer to the qualitatively different and more practically relevant regime of approximate state transfer.
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All authors Twesh Upadhyaya, T. C. Mooney, Yifan Hong, Alexey V. Gorshkov
Quantum Physics
Proof of the hiding conjecture for Gaussian boson sampling with an arbitrary number of squeezed input modes
Laura Shou, Alexey V. Gorshkov, Victor Galitski et al. (+1 more)
Gaussian
boson sampling (GBS) is a sampling task proposed to demonstrate
quantum advantage. We consider Gaussian
boson sampling on $M$ optical modes, with $K$ equally squeezed input modes and $N$ observed
photon counts. We complete the proof of the hiding
conjecture for Gaussian
boson sampling with an arbitrary number of squeezers $K$, which is a part of the argument for classical hardness of GBS. In particular, we show that for any $K$ and $N=o(\sqrt{K})$, the symmetric product $MK^{-1/2}U_{NK}U_{NK}^T$, for $U_{NK}$ the top left $N\times K$ submatrix of an $M\times M$ Haar random
unitary $U$, is close in total variation distance to both an $N\times N$ symmetric complex Gaussian
matrix $\mathbf G$ with independent entries, and the symmetric product $GG^T/\sqrt{K}$ for $G$ an $N\times K$
matrix of iid standard complex Gaussians. We show however that the density-based instance generating method of [Aaronson and Arkhipov, Theory Comput. 9, 143 (2013), Lemma 5.8] used to efficiently implement a hiding procedure fails for Gaussian
boson sampling with $K=cM$ if $c<1/2$. Instead we use approximate instance generating to implement the hiding for the usual classical hardness reduction.
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All authors Laura Shou, Alexey V. Gorshkov, Victor Galitski, Sarah H. Miller
High Energy Physics (Phenomenology)
Heavy quark transport in quark-gluon plasma beyond the non-relativistic limit
Krishna Rajagopal, Bruno Scheihing-Hitschfeld and Urs Achim Wiedemann
The dynamics of heavy
quarks in
quark-
gluon plasma (QGP) formed in heavy ion collisions provide a unique window to characterize its properties. Existing approaches to describe heavy
quarks in medium rely either on quasiparticle-based models of QGP, or on assuming that the momentum transfer from the medium follows Gaussian statistics. However, neither of these assumptions can be taken for granted in QCD. In fact, in the prototypical theory that is strongly coupled $\mathcal{N}=4$ SYM, it has been long known there are no momentum-carrying quasiparticles, and furthermore, we have recently shown that the momentum transfer from the medium is far from being Gaussian [arXiv:2501.06289]. Since then, we showed that the asymmetry of said momentum transfer between energy loss and energy gain – which affects all moments of the distribution, not only its Gaussian characteristics – is, in fact, universal [arXiv:2504.21139]. Therefore, in order to connect the initial heavy
quark production cross section with the final
hadron spectrum in a way that is consistent with QFT principles, new methods are needed. In this talk, we present a new transport description of heavy
quarks that encodes all of the non-Gaussian features of the momentum transfer from the medium, all of which can be defined and in principle calculated in QCD, without relying on any assumptions regarding the strength of the coupling. As a demonstrative example, we discuss heavy
quark equilibration in $\mathcal{N}=4$ SYM. This paves the way towards extracting novel information about fundamental properties of QGP.
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Strongly Correlated Electrons
Junyi Cao, Ramanjit Sohal, Angela Kou et al. (+1 more)
Fractional
quantum Hall-
superconductor (FQH-SC)
heterostructures are predicted to host defect-bound parafermion zero modes (PZMs). We propose two related configurations to probe their fusion structure. In a Josephson junction coupled to a single
quantum point contact (QPC), quasiparticle tunneling switches the defect fusion channel, producing
stochastic transitions between branches of the fractional Josephson spectrum.
Embedding the junction in a two-QPC Fabry-Pérot interferometer provides a complementary probe. Weak zero mode tunneling produces fusion-channel-dependent interference while strong tunneling makes the interferometer probe a superposition of fusion channels and strongly suppresses the signal: in the topological limit it vanishes exactly, revealing the defects' non-Abelian nature even when the parent FQH state is Abelian.
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All authors Junyi Cao, Ramanjit Sohal, Angela Kou, Eduardo Fradkin
Astrophysics of Galaxies
Low Ly$\alpha$ Visibility in Galaxy Overdensities: Reionization Topology and Neutral-Fraction Ceilings from DIVER over $4.8<z<11$
Yongda Zhu, Xiaohui Fan, Laura C. Keating et al. (+19 more)
Ly-alpha emission is widely used to trace
cosmic reionization, but its interpretation depends on how Ly-alpha visibility varies with
galaxy environment. We use deep JWST/NIRSpec observations from Deep Insights into UV Spectroscopy at the Epoch of Reionization (DIVER) in GOODS-N to measure Ly-alpha visibility for 250
galaxies at 4.8<z<11. The sample contains 84 Ly-alpha detections, including 44 strong emitters with rest-frame Ly-alpha equivalent width W_Lyalpha>25 A. We combine these measurements with H-alpha and [O III] emitters from JWST/NIRCam wide-field slitless spectroscopy to map the density field around each DIVER
galaxy.
Galaxies with high Ly-alpha equivalent widths (W_Lyalpha>25 A) or high effective Ly-alpha escape fractions (f_esc,Lyalpha^eff>0.05) tend to lie farther from nearby H-alpha and [O III] emitters than
galaxies with lower Ly-alpha visibility. The clearest signal occurs near the prominent GOODS-N overdensity at z~5.2, where fewer than 15% of
galaxies show strong Ly-alpha emission. This trend is opposite to the simplest inside-out reionization expectation that overdensities produce larger ionized regions and enhance Ly-alpha visibility. Possible explanations include circumgalactic and local intergalactic opacity, dense absorbers, and gas kinematics. We also derive an empirical upper envelope for f_esc,Lyalpha^eff and calibrate it with reionization simulations. Interpreting this envelope as a limiting IGM-attenuation signal gives neutral-fraction ceilings of <x_HI>_max=0.36, 0.76, 0.74, 0.84, and 1.0 at z~5.2, 5.8, 6.7, 7.7, and 9.8, respectively. The z~8 ceiling disfavors an almost completely neutral IGM at this epoch. These results support patchy reionization already underway by z~8 and show that
galaxy Ly-alpha visibility encodes both large-scale ionization
topology and near-source gas structure.
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All authors Yongda Zhu, Xiaohui Fan, Laura C. Keating, George D. Becker, Eiichi Egami, Xiaojing Lin, Fengwu Sun, Christopher Cain, Marcia J. Rieke, Andrew J. Bunker, Sijia Cai, Francesco D'Eugenio, Jakob M. Helton, Xiangyu Jin, Mingyu Li, Zheng Ma, Roberto Maiolino, Pierluigi Rinaldi, Christopher N. A. Willmer, Yunjing Wu, Zihao Wu, Junyu Zhang
Quantum Physics
Dissipation-enhanced scrambling in the SYK model coupled to a lossy cavity
Pietro Pelliconi, Bastien Lapierre and Shinsei Ryu
We study the Yukawa-Sachdev-Ye-Kitaev model, a disordered model of $N$ Majorana
fermions and $R=\gamma N$
bosons in which the
bosons are linearly coupled to independent realizations of SYK $p$-body interactions, in the presence of dissipation, modeled by a Lindblad master equation. Motivated by recent proposals for implementing SYK models in
quantum simulators, we focus on bosonic leakage at rate $\kappa$. Initializing the system in the steady state, we analyze the late-time fermionic relaxation rate and the Lyapunov exponent, solving the large-$N$ theory both numerically and for $p$ large, finding a rich landscape of dynamical behaviors. Most notably, the Lyapunov exponent remains positive for every value of $\kappa$ and, for $p>2$, can even grow as $\kappa$ increases. The QED case $p=2$, which lies between the fully chaotic regime $p>2$ and the integrable case $p=1$, exhibits special features. We also identify a critical value of the
boson-to-
fermion ratio $\gamma_c \approx 2/p^2$ separating distinct dynamical regimes.
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High Energy Physics (Theory)
3D Einstein action from 6D Kodaira-Spencer gravity
Johanna Erdmenger, Jonathan Karl, Jani Kastikainen et al. (+1 more)
In view of
embedding 3D
gravity into topological string theory, we show that the dimensional reduction of 6D Kodaira-Spencer
gravity on $\text{AdS}_3\times S^3$, i.e. the low-energy description of twisted holography, contains a subsector that coincides with the action of
chiral 3D
gravity on $\text{AdS}_3$. Furthermore, we show that the full 3D Einstein action is obtained as the reduction of two independent complex-conjugate copies of 6D Kodaira-Spencer
gravity. We perform the dimensional reduction explicitly at the level of the classical actions, extending our previous work that related the equations of motion of the two theories. Our reduction procedure is based on a novel rewriting of the non-local 6D Kodaira-Spencer action as a local 6D holomorphic Chern-Simons action for the gauge group $\mathrm{SL}(2,\mathbb{C})$, valid within a subsector of complex structure deformations that we identify. Our results provide a necessary step toward
embedding the Euclidean path integral of 3D
gravity into topological string theory.
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All authors Johanna Erdmenger, Jonathan Karl, Jani Kastikainen, Henri Scheppach
Astrophysics of Galaxies
The THESAN-ZOOM project: clumpiness of high-redshift galaxies and its connection to bursty star formation
Zihao Wang, Xuejian Shen, Rahul Kannan et al. (+12 more)
Recent JWST observations have revealed diverse high-
redshift galaxy morphologies, including a population with irregular and clumpy structures. The physical origin of these structures, and the extent to which observational biases shape their appearance, remain uncertain. We present a power-spectrum-based method for quantifying
galaxy clumpiness across spatial scales, using the radiation-hydrodynamic simulation suite THESAN-ZOOM, which employs a state-of-the-art
galaxy formation model that resolves the multiphase interstellar medium (ISM). Although the total
stellar mass distributions in THESAN-ZOOM
galaxies are usually smooth, clumpy structures appear in the H$\alpha$, far-ultraviolet (FUV), and optical light distributions. Tracers sensitive to shorter-timescale
star formation exhibit more pronounced small-scale structure ($\sim10^{2}$–$10^{3}{\rm pc}$). The corresponding projected light spectra follow $P(k)\propto k^{-1}$ to $k^{-2}$, with progressively shallower slopes for tracers sensitive to more recent
star formation, reflecting enhanced small-scale power and greater spatial intermittency in young
stellar populations. This behaviour is consistent with a highly compressible, shock-dominated ISM in which
stellar feedback and
outflows reorganise dense gas into filamentary and clumpy structures. We also find that
galaxy clumpiness depends on the treatment of
stellar feedback. Weaker early
stellar feedback enhances small-scale power in both the mass and light distributions. Clumpiness also varies strongly over the bursty
star formation cycle, implying that observed samples may be biased towards
galaxies caught in phases of elevated
star formation.
Galaxy clumpiness, therefore, could provide a complementary probe of the bursty
star formation in the early Universe.
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All authors Zihao Wang, Xuejian Shen, Rahul Kannan, Ewald Puchwein, Aaron Smith, Josh Borrow, Enrico Garaldi, Laura Keating, Mark Vogelsberger, Oliver Zier, William McClymont, Sandro Tacchella, Fangzhou Jiang, Hui Li, Lars Hernquist
Cosmology and Nongalactic Astrophysics
The Challenge of Observing Patchy Reionization with CMB Optical-Depth Fluctuations
Nick Takoudes, Hanjue Zhu and Nickolay Y. Gnedin
Spatial fluctuations in the Thomson optical depth encode information about the inhomogeneous nature of
cosmic reionization. We compute the optical-depth angular power spectrum, $C_\ell^{\tau\tau}$, using past lightcones constructed from five
Cosmic Reionization on Computers (CROC) radiation-hydrodynamical simulations. By decomposing the electron-density field into patchy and density components, we quantify the separate contributions of ionization-fraction and
baryon-density fluctuations to the optical-depth anisotropy. Because the simulations end at $z\approx5$, we supplement the reionization-era signal with an analytic estimate of the fully ionized low-
redshift contribution. We find that
baryon-density fluctuations dominate the high-
redshift signal over most angular scales, while the accumulated low-
redshift contribution exceeds the high-
redshift signal across the full multipole range considered. Our results demonstrate that a significant fraction of the optical-depth power is not uniquely associated with reionization morphology, implying that future interpretations of $C_\ell^{\tau\tau}$ must account for the density contribution in addition to patchy ionization.
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Quantum Physics
Quantum Gaussian processes for prediction of channel observations
Jonas Jäger, Yaroslav Khmelnitskiy, Paolo Braccia et al. (+4 more)
Given a set of input states, we consider the task of predicting the expectation value of a Pauli observable at the output of an unknown
quantum evolution, using only a limited number of measurements. Recently,
quantum Gaussian process (QGP) regression was introduced for this task across various classes of
unitary evolution. Here, we extend the QGP framework beyond
unitary dynamics. In particular, we prove convergence of the channel's outputs to a QGP and derive the associated closed-form kernel under a uniform (Lebesgue measure) prior over
quantum channels. The kernel's dimensional factor, however, dictates the required observation precision. While manageable when the channel and observable are restricted to small subsystems, exponential suppression precludes learning when the subsystem grows extensively with the system size. Since the Lebesgue prior is overly broad for many applications, we propose an empirical Bayes heuristic that replaces the dimensional factor with a learnable scale parameter while retaining the kernel's state-overlap correlation structure. In numerical simulations of up to 64
qubits, channel QGP regression with the Lebesgue kernel exhibits a strong inductive bias for local channels, enabling faithful extrapolation. For global 64-
qubit channels, the rescaled kernel restores learnability, with predictions improving systematically with the shot budget. Results from a noisy
quantum computer further demonstrate the robustness of QGP regression under experimental conditions. Beyond regression, we validate QGPs as
Bayesian-optimization surrogates for state preparation under noisy XXZ dynamics.
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All authors Jonas Jäger, Yaroslav Khmelnitskiy, Paolo Braccia, Artur Miroszewski, Diego García-Martín, M. Cerezo, Piotr Czarnik
High Energy Physics (Theory)
Holographic Local Operator Quenches with Conserved Momentum and Spin
Pawel Caputa, Pedro Castellini Grand, Justin R. David et al. (+1 more)
We investigate the
holographic dictionary relating point particles carrying longitudinal momentum or angular momentum in asymptotically AdS$_3$ spacetimes to suitably regulated, time-evolved states created by local primary operators in the dual two-dimensional conformal field theory (2D CFT). We find that asymmetric left/right Euclidean smearing of local operators produces states carrying momentum, and the corresponding bulk excitation is a particle with conserved momentum. We compute the energy density and
entanglement entropy in these states and in their dual back-reacted geometries, finding exact agreement between the CFT and
gravity descriptions. We further extend this correspondence to particles with intrinsic
spin, whose CFT duals are primary operators with unequal holomorphic and anti-holomorphic scaling dimensions. We again find a precise match between CFT and
holographic calculations of energy densities and
entanglement entropies. Finally, we explore applications of these setups beyond holography by deriving the
evolution of Rényi
entropies in 2D rational CFTs and introducing a new class of local
quantum quench protocols with conserved longitudinal or angular momentum.
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All authors Pawel Caputa, Pedro Castellini Grand, Justin R. David, Rahul Metya
Solar and Stellar Astrophysics
Multi-lane type II radio bursts: Insights into shock propagation in the corona
Nadiya K., Divya Paliwal and Anshu Kumari
Type II
solar radio bursts are considered as the signatures of the coronal shocks. These bursts are generated from
plasma waves excited by magnetohydrodynamic (MHD) shocks, and then converted into
radio waves at the local
plasma frequency and/or its harmonics. Hence, these bursts often have fundamental-harmonic (FH) and band-splitting (SB) structures, which provide insights into shock generation and propagation in the corona, hence, in turn, the corresponding coronal conditions. In the present study, we analysed an unusual multi-lane type II burst observed with ground-based
solar radio spectrographs on May 29, 2024, between 14:24 and 14:43 UT. The start and end frequencies of the type II burst were 450 MHz and 25 MHz, respectively. By combining spectral information with
radio imaging data, we found that
radio waves were escaping from the corona via emissions from distinct shock regions. In addition, along with the traditional FH and SB, there were multi-lane structures in the type II bursts. Our analysis suggests complex, inhomogeneous shock dynamics near the leading edge (LE) of the coronal mass ejection (CME). This indicates that the
plasma material compresses more strongly in these forefront regions. This was confirmed by
radio imaging observations, which showed that the higher-frequency emission occurred at a higher altitude than the lower-frequency emission. Our results suggest that the shock geometry and
plasma inhomogeneity play an important role in the generation of type II bursts, leading to traditional fundamental-harmonic split-band (FH-SB) pairs with additional splitting in the type II bands.
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High Energy Physics (Theory)
Constrained Scenarios of Non-Commutative Schwarzschild Black Holes with Global Monopoles from Van der Waals Behaviors
Ismail Benyaich and Maryem Jemri
Combining thermodynamics and optics, we investigate the Van der Waals behaviors of non-commutative Schwarzschild black holes with global monopoles. First, we examine the constrained thermodynamic recovering such properties. Using these thermodynamic results, we approach the shadows by merging Event Horizon
Telescope findings and the Van der Waals limits. In this context, we provide a machine learning study to determine the compatibility with the empirical data of M87^*, SgrA^*_{\mathrm{VLTI}}, and SgrA^*_{\mathrm{Keck}} black holes. As a result, we find that such a proposed model matches with the M87^* observational data.
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Physics and Society
Rural Commute Patterns
Mohamed Khalafalla, Doreen Kobelo, Thobias Sando et al. (+1 more)
Transportation provides access to employment opportunities and essential services such as healthcare services, while urban areas have various transportation options, the situation differs in rural areas. Rural residents often have longer commute distances, limited access to public transit, and extended waiting times for public transportation if they exist, which can significantly impact their access to vital services and job opportunities. This study used data from the 2017 NHTS survey to examine the commuting patterns in rural areas by utilizing multinomial logistic regression to determine how various factors impact the choice of mode of transport in rural areas. Findings from this study revealed a higher dependency, 92.1%, on using personal vehicles when making trips in rural areas. Multinomial logistic regression results showed that socio-demographics, household, and trip characteristics affect the mode of transport used in a trip. Older adults, females, and individuals with higher education levels than high school graduates are less likely to use public transit when making trips. For household characteristics, the availability of vehicles in a household and households with higher income levels have lower probabilities of making a trip using public transit. Longer trip distances reduce the likelihood of a trip using active commuting modes such as walking and biking. These findings provide insights into understanding the transportation behaviors in rural areas and provide knowledge to be used in the planning and developing of transportation projects to promote equitable and accessible transportation in rural areas.
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All authors Mohamed Khalafalla, Doreen Kobelo, Thobias Sando, Janeroza Matyeni
Popular Physics
The 1908 Tunguska event in data of the nearest weather station
Andrei Ol'khovatov
This paper is a continuation of a series of works, devoted to various aspects of the 1908 Tunguska event. In this paper data is discussed from a weather station in the settlement of Kezma. This weather station was the nearest one to the epicenter of the 1908 Tunguska event. The station was about 215 km southwards from the epicenter. Also eyewitness accounts from Kezhma and some places on the Angara River are considered. The paper demonstrates the diversity of optical manifestations of the 1908 Tunguska event reported from Kezhma and its surroundings. A note by the observer of the weather station in Kezhma, concerning, in particular, the appearance of the two huge fiery circles is very important. The weather log of the weather station shows that the Tunguska event occurred during the sharp increase in cloud cover and deteriorating weather. At the beginning of July, rains and thunderstorms, including hail, began according to the weather log. In the opinion of the author, the data of the Kezhma weather station and the eyewitness accounts are in agreement with the geophysical interpretation of the 1908 Tunguska event. In any case, the meteorological factor is an important aspect of the Tunguska event, and so it deserves detailed research.
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High Energy Physics (Phenomenology)
On trace invariance and energy-dependent entanglement in muon decay
Saulo Carneiro and Fernando César Sobrinho
We revisit a proposed correction to the
muon magnetic anomaly measurement and compare it with energy-binned scans reported by the Fermilab $g-2$ collaboration. The central point is that, for a relativistic three-body decay inferred from an ensemble of detected positrons, the relevant
neutrino partial trace is defined on the asymptotic state at the detector, not on an idealised state at the decay vertex. Because the fitted positron sample mixes events with different decay times, flight times, energies and acceptances, tracing over the unobserved
neutrino helicities leaves a time-dependent mixed state in the observed sector. Using angular-momentum balance, we obtain an energy-dependent correction in the positron energy interval $E_p \in (1.5,2.9)$ GeV. The corrected experimental interval for the
muon anomaly moves towards the BaBar- and $\tau$-based determinations, while remaining compatible at the $1\sigma$ level with both data-driven and
lattice-based Standard Model evaluations. We then fit digitised public $R(E_p)$ scans for Fermilab's runs $1$ to $6$, with two one-parameter hypotheses: a constant shift and the
entanglement-motivated energy-dependent shift. Within digitisation accuracy, the differences in $\chi^2$ remain modest and the current binned data do not provide decisive discrimination between them.
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Mesoscale and Nanoscale Physics
Extension of the Shockley-Queisser Limit for Nanostructured Solar Cells
Rivo Herivola Manjakamanana Ravelonjato, Jean Patrice Rakotoniaina, Ravo Tokiniaina Ranaivoson et al. (+1 more)
This article extends the Shockley-Queisser limit to nanostructured
solar cells using the
quantum phase space formalism. The parameter B_ll represents the momentum variance in each confinement direction and acts as a variance-covariance
matrix linking the nanostructure geometry to thermodynamic properties. Electron-electron interactions are included via an exchange-correlation energy with an adjustable coefficient theta. The authors derive an analytical expression for the maximum efficiency as a function of size, shape, temperature, and doping. For the cylindrical geometry, the exact confinement energy uses the first zero of the Bessel function j_0,1. Numerical simulations are performed with Python 3.8.1, NumPy, and Matplotlib for PbS
quantum dots in four geometries: cube, square parallelepiped, cylinder, and sphere. The integral is evaluated using an exact convergent series expansion. Results show that the maximum efficiency reaches 48.7 percent for a 5 nanometre cube, 49.0 percent for flattened parallelepiped and cylinder shapes, and 49.1 percent for a 3 nanometre sphere. These values greatly exceed the bulk PbS efficiency of 15.8 percent and surpass classical Shockley-Queisser limits. For constant-volume shapes, two efficiency peaks appear corresponding to different aspect ratios. The model correctly returns to classical values for large sizes. This approach provides a theoretical framework for optimising nanostructured
solar cells and demonstrates that
quantum confinement offers a promising route to surpass traditional photovoltaic limits.
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All authors Rivo Herivola Manjakamanana Ravelonjato, Jean Patrice Rakotoniaina, Ravo Tokiniaina Ranaivoson, Wilfrid Chrysante Solofoarisina
Materials Science
Multi-Tool Robotics Enables In-Situ Sample Manipulation for Time-Resolved Synchrotron Measurements
Aditya Bondada, Elizabeth M. Wall, Eric Yuan Xiao et al. (+4 more)
The high
photon flux at synchrotron beamlines allows for the measurement of fast dynamical processes. However, beamline radiation-safety protocols prohibit human intervention during X-ray experiments, limiting the ability to perform versatile real-time sample manipulations during continuous data acquisition. Here we present a robotic platform at an X-ray scattering beamline to enable real-time sample handling and processing in the experimental hutch, revealing previously inaccessible transient in-situ dynamics in perovskite thin films. This modular multi-tool robotic architecture enables in-hutch sample manipulation beyond human-access constraints, establishing a foundation for automated and autonomous synchrotron experimentation.
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All authors Aditya Bondada, Elizabeth M. Wall, Eric Yuan Xiao, Quinn C. Burlingame, Yueh-Lin Loo, Esther H. R. Tsai, Ruipeng Li
General Relativity and Quantum Cosmology
Quasinormal Modes, Partial Transmission Probabilities, and Hod's Conjecture of Charged Black Holes in Perfect Fluid Dark Matter within Kalb-Ramond Gravity
Zongyuan Qin and Zheng-Wen Long
Within the Kalb-Ramond field-induced Lorentz-violating
gravity, we investigate the perturbation dynamics and quasinormal mode (QNM) spectra of a charged black hole immersed in perfect fluid dark matter. The background spacetime is characterized by the Lorentz-violating parameter tau, the electric charge Q/M, and the dark matter parameter lambda/M. Owing to the non-zero
vacuum expectation value of the KR field, the metric function approaches 1/(1-tau) at infinity instead of 1, rendering the spacetime non-asymptotically flat. Under the test-field approximation, the equations of motion for three types of perturbations (scalar, electromagnetic, and axial gravitational) are reduced to Schrodinger-type radial equations with single-peak effective potentials. The QNM frequencies are cross-validated using the sixth-order WKB method and the time-domain Prony method, while the partial transmission probabilities are computed within the WKB scattering framework. Parameter scans show that tau exerts the strongest influence on the QNM spectrum, followed by lambda/M, with Q/M having the weakest effect; the same ordering holds for the partial transmission probabilities. Under the same parameters, the QNM frequencies of the three perturbations follow the order scalar > electromagnetic > gravitational, whereas the transmission probabilities exhibit the reverse order, reflecting the different impact of the effective potential height on the oscillation frequency and on the transmission probability. The Hod
conjecture |Im(omega)| <= pi T_H holds throughout the parameter range examined.
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Astrophysics of Galaxies
Diffuse HI emission in the circumgalactic medium of NGC891 and NGC4565 - III: azimuthal profiles
Mary Rickel, Sanskriti Das, Nickolas M. Pingel et al. (+4 more)
Diffuse HI emission in the circumgalactic medium (CGM) of NGC891 and NGC4565 has been previously shown to trace an inflow along minor axes pointings and to co-rotate with the HI disk along major axes pointings out to ~100 kpc (Das2020b,Das2024a). To obtain a 360$^\circ$ view of the inner neutral CGM ($\rm < 25 kpc$ for NGC891, $\rm < 30 kpc$ for NGC4565), we perform deep stare observations with the Green Bank
Telescope (GBT) along the off-axes, 45$^\circ$ between principal axes, achieving a 5$\sigma$ column density sensitivity of $1.1-1.2 x 10^{17} \rm cm^{-2}$ over a 20 kms$^{-1}$ velocity width. While detecting HI emission in the inner CGM with single-dish
telescopes is common, separating the true CGM emission from disk contamination is extremely challenging and has so far been largely unsuccessful. To achieve that, we compare our single-dish detections to deep interferometric maps from the Westerbork Synthesis
Radio Telescope (WSRT) HALOGAS survey, and improve upon our previous methods by incorporating velocity offset corrections and channel-wise brightness-temperature scaling. We find that $30-38$ % and $18-28$ % of the emission detected by the GBT cannot be explained by WSRT in NGC891 and NGC4565, respectively, implying a true CGM detection. There is $4-6$ ($3-7$) times more HI along the off-axes than major (minor) axes, nullifying the common assumption of azimuthal
symmetry of the neutral CGM. The velocity profile of the diffuse inner CGM suggests a lagged co-rotation with the HI disk in both
galaxies. This exercise illustrates the power of deep observation and careful cross-instrument comparisons to characterize the diffuse HI in the CGM.
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All authors Mary Rickel, Sanskriti Das, Nickolas M. Pingel, D. J. Pisano, Adam Leroy, Smita Mathur, George Heald
Strongly Correlated Electrons
Unconventional bond- and current-density waves on hexagonal lattices
Andras Szabo, Hannes Braun and Laura Classen
Charge-density wave (CDW) orders are conventionally described as modulations of on-site charge at an ordering wave vector $\boldsymbol{Q}$ with
symmetry-related wave vectors typically forming a multicomponent order-parameter
manifold. Recent developments significantly broadened this phenomenology to bond and loop-current density waves, which possess nontrivial, potentially
symmetry-breaking textures within the unit
cell in addition to their spatial modulation at $\boldsymbol{Q}$. Such textures arise from particle-hole condensates with nonzero angular momentum, analogous to unconventional superconductivity, and their
symmetries are described by the little group $G_{\boldsymbol{Q}}$. In this work, we develop a framework for unconventional CDW phases that simultaneously incorporates the local
symmetries described by little group and the presence of multiple
symmetry-related ordering wave vectors, also known as the
star. The resulting multicomponent order parameter transforms under representations of the full space group induced from irreducible representations of $G_{\boldsymbol{Q}}$. We apply this framework to two-dimensional
lattices with sixfold
symmetry and ordering wave vectors along high-
symmetry lines, and derive the corresponding Landau free energies. As a microscopic example, we demonstrate the emergence of unconventional bond and loop-current orders from electronic interactions on the triangular
lattice within the random phase approximation, and determine their ground states by microscopically evaluating the relevant coefficients in the free energy. Our framework provides a systematic route to describing unconventional modulated phases and can be readily extended to more complex
lattices.
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Quantum Gases
Electrostriction in a Bose-Einstein Condensate of Dipolar Molecules
Haneul Kwak, Ian Stevenson, Weijun Yuan et al. (+5 more)
The recent creation of a Bose-Einstein condensate (BEC) of dipolar molecules has opened a new frontier for many-body
quantum systems in which dipolar interactions can drive novel self-organization phenomena. Here, we observe electrostriction in a molecular BEC, an elliptical deformation driven by anisotropic dipolar interactions. We use double microwave dressing, involving $\sigma$- and $\pi$-polarized fields, to control non-axially symmetric dipolar interactions. We compare the experimental observations of electrostriction to a model based on an extended Gross-Pitaevskii equation and find excellent agreement in the regime of weak to moderate interactions. Using electrostriction, we demonstrate that the molecular BEC can be torqued by dynamically changing the orientation of the elliptical $\sigma$ microwave field. This provides a route to setting molecular
quantum gases into rotation, opening opportunities to probe vorticity, superfluidity, and supersolidity in strongly dipolar matter.
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All authors Haneul Kwak, Ian Stevenson, Weijun Yuan, Siwei Zhang, Asaf Toprakci, Lin Su, Tijs Karman, Sebastian Will
Strongly Correlated Electrons
Chiral bosonic mean-field Ansatz and spin dynamics in spin-1 Kitaev magnets
Daiki Sasamoto, Arnaud Ralko, Jaime Merino et al. (+1 more)
The Kitaev model is a paradigmatic system for realizing
quantum spin liquids, but its higher-
spin extensions are not exactly solvable, and their
spin dynamics is less well understood than in the
spin-1/2 case. In this work, we reexamine a previously introduced triplet-pairing $\phi_t = \pi/2$ phase pattern for the
antiferromagnetic $S = 1$ Kitaev model and extend the analysis to weak symmetric off-diagonal exchanges $\Gamma$ and $\Gamma'$. Using a bond-operator formulation of Schwinger-
boson mean-field theory, we calculate the dynamical
spin structure factor for the triplet 0-flux and triplet $\pi/2$-flux Ansätze with a
spin-correlation scheme appropriate for Kitaev interactions. In the pure Kitaev limit, the $\pi/2$-flux Ansatz yields a flatter spectrum than the 0-flux Ansatz. The real-space
spin correlations show that the $\pi/2$-flux Ansatz suppresses longer-distance correlations more strongly than the 0-flux Ansatz, yielding a correlation pattern closer to the short-ranged form expected in the Kitaev limit. This comparison shows that the flatness of $S(\boldsymbol{q}, \omega)$ is tied to short-ranged
spin correlations and is therefore an important consistency check, although it is not, by itself, a diagnostic of time-reversal-
symmetry breaking. We then study weak off-diagonal exchanges along $\Gamma' = \Gamma$ near the pure Kitaev limit, taking the same-sign relation from analyses of candidate
spin-1 Kitaev materials. Gapped solutions are obtained within the constrained $\pi/2$-flux
manifold, and the spectra share the qualitative energy- and momentum-space features found by finite-size exact diagonalization. Taken together, these results support the triplet $\pi/2$-flux
chiral bosonic Ansatz as a useful mean-field description of
spin dynamics near the
antiferromagnetic $S = 1$ Kitaev limit with weak off-diagonal exchanges.
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All authors Daiki Sasamoto, Arnaud Ralko, Jaime Merino, Joji Nasu
Instrumentation and Methods for Astrophysics
Effects of manufacturing tolerances on the performance of metamaterial microwave anti-reflection coatings
Rustam Balafendiev, Miranda Eiben and Jon E. Gudmundsson
Metamaterial anti-reflection coatings (ARC) are used in a variety of applications, including: lenses, filters, and absorbers. Typically, the design of a given ARC is done within an infinite medium approximation, which presupposes that every unit
cell on the interface is identical. However, in realistic applications, the geometry of a given ARC usually has some degree of variability, be it due to the shape of the surface inherent to the application, like in a lens, or manufacturing tolerances. This variation may alter the performance of the optical element in unanticipated ways, by creating additional scattering, enabling diffractive maxima that would normally be absent and, most crucially, changing the transparency of the ARC as a function of frequency. In this work we utilize full-wave modeling of finite samples of plastic which are matched with free space using a metamaterial ARC on both of their interfaces. By adding a degree of randomness to the ARC geometry we attempt to characterize the extent to which a given variation affects the expected performance of an ARC.
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