Tootfinder

New ultralight scalar particles and the mass-radius relation of white dwarfs -- the important role of Sirius B
Kai Bartnick, Detlev Koester, Rolf-Peter Kudritzki, Konstantin Springmann, Stefan Stelzl, Andreas Weiler
https://arxiv.org/abs/2510.06312

New ultralight scalar particles and the mass-radius relation of white dwarfs -- the important role of Sirius B
We present the equation of state for two classes of new ultralight particles, a scalar field coupling to electrons and a light $\mathbb{Z}_\mathcal{N}$ QCD axion field coupling to nucleons. Both are potential candidates for dark matter. Using the scalar modified equations of state, we calculate models for white dwarf stars and compare their radii and masses with observed mass-radius data. The comparison results in stringent constraints on the masses of the particles and the coupling parameters.…

The high order spectral radius of graphs without long cycles or paths
Yuntian Wang, Lizhu Sun, Changjiang Bu
https://arxiv.org/abs/2510.04461 https://arxiv…

The high order spectral radius of graphs without long cycles or paths
In 1959, Erdős and Gallai established two classic theorems, which determine the maximum number of edges in an $n$-vertex graph with no cycles of length at least $k$, and in an $n$-vertex graph with no paths on $k$ vertices, respectively. Subsequently, generalized and spectral versions of the Erdős-Gallai theorems have been investigated. A concept of a high order spectral radius for graphs was introduced in 2023, defined as the spectral radius of a tensor and termed the $t$-clique spectral rad…

"It's now been a week, and I checked again: Joshua's 'HIGHLY secure' server is still running a version of Apache with multiple known critical vulnerabilities. And even with plenty of time to fix the issue, he still hasn't."
https://micahflee.com/icebl…

ICEBlock handled my vulnerability report in the worst possible way
Last week, I wrote about how Joshua Aaron's ICEBlock app, which allows people to anonymously report ICE sightings within a 5-mile radius, is – unfortunately, and despite apparent good intentions – activism theater. This was based on Joshua's talk at HOPE where he made it clear that he isn't taking the advice

Observational constraints on f(Q,T) gravity from the mass-radius relation and stability of compact stars
S. K. Maurya, Abdul Aziz, Ksh. Newton Singh, G. Mustafa, Y. Sekhmani, Saibal Ray
https://arxiv.org/abs/2510.06003

Observational constraints on f(Q,T) gravity from the mass-radius relation and stability of compact stars
In this investigation we examine the astrophysical consequences of the influence of pressure anisotropy on the physical properties of observed pulsars within the background of $f(Q,T)$ gravity by choosing a specific form $f(Q, T)=ψ_1\, Q + ψ_2 T$, where $ψ_1$ and $ψ_2$ are the model parameters. Initially, we solve the modified field equations for anisotropic stellar configurations by assuming the physically valid metric potential along with anisotropic function for the distribution of the i…

Resolution-Corrected White Dwarf Gravitational Redshifts Validate SDSS-V Wavelength Calibration and Enable Accurate Mass-Radius Tests
Stefan M. Arseneau, J. J. Hermes, Nadia L. Zakamska, Kareem El-Badry, Nicole R. Crumpler, Vedant Chandra, Gautham Adamane Pallathadka, Carles Badenes, Boris T. Gaensicke, Nicola Gentile Fusillo
https://arxiv…

Resolution-Corrected White Dwarf Gravitational Redshifts Validate SDSS-V Wavelength Calibration and Enable Accurate Mass-Radius Tests
Leveraging the large sample size of low-resolution spectroscopic surveys to constrain white dwarf stellar structure requires an accurate understanding of the shapes of hydrogen absorption lines, which are pressure broadened by the Stark effect. Using data from both the Sloan Digital Sky Survey and the Type Ia Supernova Progenitor Survey, we show that substantial biases (5-15 km/s) exist in radial velocity measurements made from observations at low spectral resolution relative to similar measure…

Quantitative Evaluation of the delta-Eddington, Hapke, and Shkuratov Models for Predicting the Albedo and Inferring the Grain Radius of Ice
Aditya R. Khuller, Al Emran
https://arxiv.org/abs/2509.06224 …

Quantitative Evaluation of the delta-Eddington, Hapke, and Shkuratov Models for Predicting the Albedo and Inferring the Grain Radius of Ice
Determining the physical properties of ices across the solar system is essential for understanding the surface dynamics, volatile transport, and climate evolution on ice-covered planetary bodies. Here, we use well-constrained measurements of snow that has metamorphosed into coarse-grained firn and bubbly glacier ice in East Antarctica to test three commonly-used radiative transfer models: delta-Eddington, Hapke, and Shkuratov. Using the measured optical properties, we find that the delta-Edding…

Mutual Support by Sensor-Attacker Team for a Passive Target
Prajakta Surve, Shaunak D. Bopardikar, Alexander Von Moll, Isaac Weintraub, David W. Casbeer
https://arxiv.org/abs/2509.06092

Mutual Support by Sensor-Attacker Team for a Passive Target
We introduce a pursuit game played between a team of a sensor and an attacker and a mobile target in the unbounded Euclidean plane. The target is faster than the sensor, but slower than the attacker. The sensor's objective is to keep the target within a sensing radius so that the attacker can capture the target, whereas the target seeks to escape by reaching beyond the sensing radius from the sensor without getting captured by the attacker. We assume that as long as the target is within the sen…

Moments of finitary factor maps between Bernoulli processes
Uri Gabor
https://arxiv.org/abs/2509.06018 https://arxiv.org/pdf/2509.06018

Moments of finitary factor maps between Bernoulli processes
The problem of what moments can exist for the coding radius of a finitary map between two i.i.d. processes, has been extensively studied in the case of $\mathbb{Z}$-processes. Here we treat this problem for factor maps between $\mathbb{Z}^{d}$-processes ($d>1$). By modeling the homomorphism with a map between spaces of finite sequences, we extend Harvey and Peres' result, showing that for a finitary homomorphism between two i.i.d. processes of equal entropy, if the coding radius of the map has …

Suzaku observations of outskirts of nearby clusters and groups: I. electron density and gas fraction to the virial radius
Kyoko Matsushita, Marie Kondo, Kosuke Sato, Toru Sasaki, Nobuhiro Okabe, Kotaro Fukushima
https://arxiv.org/abs/2510.04523

Suzaku observations of outskirts of nearby clusters and groups: I. electron density and gas fraction to the virial radius
We present an analysis of Suzaku observations of 14 nearby galaxy clusters and groups (z < 0.06), extending radial coverage out to the virial radius (approximately r200). The sample spans a wide mass range, from M500 about 2x10^13 to 7x10^14 solar masses, and includes well-studied systems such as Coma, Perseus, and Virgo. We carefully modeled all background components, including the soft X-ray foregrounds (the Local Hot Bubble, Milky Way Halo, and super-virial temperature components), the cosmi…

Unitary Quantum Cellular Automata for Density Classification
Pedro C. S. Costa, Yuval R. Sanders, Pedro Paulo Balbi, Gavin K. Brennen
https://arxiv.org/abs/2510.06947 https://…

Unitary Quantum Cellular Automata for Density Classification
We investigate the density classification task (DCT) -- determining the majority bit in a one-dimensional binary lattice -- within a quantum cellular automaton (CA) framework. While there is no one-dimensional two-state, radius $r \geq 1$, deterministic CA with periodic boundary conditions that solves the DCT perfectly, we explore whether a unitary quantum model can succeed. We employ the Partitioned Unitary Quantum Cellular Automaton (PUQCA), a number-conserving model, and, via evolutionary se…

Spectral Tur\'{a}n problem for $\mathcal{{K}}_{3,3}^{-}$-free signed graphs
Mingsong Qin, Dan Li
https://arxiv.org/abs/2508.05500 https://arxiv.org/pdf…

Spectral Turán problem for $\mathcal{K}_{3,3}^{-}$-free signed graphs
The classical spectral Turán problem is to determine the maximum spectral radius of an $\mathcal{F}$-free graph of order $n$. Zhai and Wang [Linear Algebra Appl, 437 (2012) 1641-1647] determined the maximum spectral radius of ${C}_{4}$-free graphs of given order. Additionally, Nikiforov obtained spectral strengthenings of the Kővari-Sós-Turán theorem [Linear Algebra Appl, 432 (2010) 1405-1411] when the forbidden graphs are complete bipartite. The spectral Turán problem concerning forbidden…

A folded string dual for the Sachdev-Ye-Kitaev model
David Vegh
https://arxiv.org/abs/2509.05435 https://arxiv.org/pdf/2509.05435

A folded string dual for the Sachdev-Ye-Kitaev model
We propose a folded string moving in rigid AdS$_2$ with imaginary radius squared as a dual of the Sachdev-Ye-Kitaev (SYK) model at its conformal fixed point. In standard AdS$_2$, the string is represented by two massless particles connected by straight string segments. The particles move at the speed of light, abruptly reversing direction at turning points. We describe the system using the lightcone coordinates of these points, with the Poisson structure obtained from the Peierls bracket. In Ad…

On the curvature bounded sphere problem in $\mathbb{R}^3$
Hongda Qiu
https://arxiv.org/abs/2507.06245 https://arxiv.org/pdf/2507.0624…

On the curvature bounded sphere problem in $\mathbb{R}^3$
We prove that if a topological sphere smoothly embedded into $\mathbb{R}^3$ with normal curvatures absolutely bounded by $1$ is contained in an open ball of radius $2$, then the region it bounds must contain a unit ball. This result suggests a potential direction for a problem formulated by D.Burago and A.Petrunin asking whether a topological sphere smoothly embedded in $\mathbb{R}^3$ with normal curvatures absolutely bounded by $1$ encloses a volume of at least $\frac{4}{3}π$. The appendix pr…

Flavor-Changing Non-Global Logarithms
Andrew J. Larkoski
https://arxiv.org/abs/2510.06031 https://arxiv.org/pdf/2510.06031…

Flavor-Changing Non-Global Logarithms
Non-global logarithms are low energy correlations between the substructure of a jet and the event in which it is immersed. We study the leading non-global logarithms that arise from soft quark--anti-quark emission and calculate their coefficient as a series in the jet radius, $R$, in arbitrary processes. We calculate the exact coefficient through quadratic order in $R$, and show that this truncation is within $5\%$ of the complete result for radii up to $R = 1$. These quark flavor-dependent non…

Elasto-viscous regime in coalescence of viscoelastic droplets
Pallavi Katre, Bimalendu Mahapatra, Manaswita Karmakar, Sarang Jagdish, Navin Kumar Chandra, Aloke Kumar
https://arxiv.org/abs/2510.06686

Elasto-viscous regime in coalescence of viscoelastic droplets
We report a regime transition in the coalescence of concentrated polymeric droplets in a pendant-pendant configuration. While Newtonian droplet coalescence has been extensively studied with distinct identification of viscous and inertial regimes, the presence of polymers introduces additional regimes governed by elasticity and molecular relaxation effects. The coalescence process is typically characterized by the neck radius, $R$, of the liquid bridge connecting the two droplets, following a po…

Influence of finite ion Larmor radius on the dynamics of weakly-collisional plasma jets colliding in magnetic arch
Artem V. Korzhimanov, Roman S. Zemskov, Sergey A. Koryagin, Mikhail E. Viktorov
https://arxiv.org/abs/2508.02519

Influence of finite ion Larmor radius on the dynamics of weakly-collisional plasma jets colliding in magnetic arch
The effect of the finite ion Larmor radius on the dynamics of two counterstreaming weakly collisional plasma flows in a magnetic field of an arch configuration is considered. Hybrid numerical simulations show that in a system whose dimensions are close to the ion Larmor radius, more intense interaction dynamics are observed, the magnetic arch experiences a significant expansion with the formation of a region with an irregular character of magnetic lines, in which magnetic reconnection processes…

A Note on Persistence Theory with Applications
N. Pant (University of Louisiana at Lafayette)
https://arxiv.org/abs/2509.06135 https://arxiv.org/pdf/2509.0…

A Note on Persistence Theory with Applications
The persistence theory has been employed by several authors in order to study persistence properties of dynamical systems generated by ordinary differential equations or maps across diverse disciplines. In this note, the author discusses a roadmap to show the persitence of dynamical systems by discussing some problems from literature, which mainly involves either dealing with spectral radius or the Lyapunov exponents.

Asymptotic models for the evolution of a circular biofilm
Diego Alonso-Or\'an, Ana Carpio, Rafael Granero-Belinch\'on
https://arxiv.org/abs/2509.07227 https://

Asymptotic models for the evolution of a circular biofilm
We study a class of lubrication-type equations modeling the spread of thin poroelastic biofilms at air/agar interfaces. Starting from a biofilm slab model, we perform a formal multi-scale asymptotic expansion to derive a reduced nonlinear evolution equation with time-dependent coefficients. First, we establish a local-in-time existence result as well as a continuation criteria. Moreover, under suitable assumptions on the radius of the biofilm, we show the existence of global in time solutions. …

Dimension-free estimates for semi-commutative discrete Hardy-Littlewood maximal operators
Xudong Lai, Yue Zhang
https://arxiv.org/abs/2508.05392 https://ar…

Dimension-free estimates for semi-commutative discrete Hardy-Littlewood maximal operators
For $2\leq p\leq \infty$, we establish dimension-free estimates for discrete dyadic Hardy-Littlewood maximal operators over Euclidean balls on semi-commutative $L_{p}$ space. In particular, when the radius is sufficiently large, these operators admit dimension-free $L_{p}$ bounds for all $1

On the meaning of the dynamo radius in giant planets with stable layers
Paula N. Wulff, Hao Cao, Jonathan M. Aurnou
https://arxiv.org/abs/2508.03861 https://

On the meaning of the dynamo radius in giant planets with stable layers
Current structure models of Jupiter and Saturn suggest that helium becomes immiscible in hydrogen in the outer part of the planets' electrically conducting regions. This likely leads to a layer in which overturning convection is inhibited due to a stabilizing compositional gradient. The presence of such a stably stratified layer impacts the location and mechanism of convectively-driven dynamo action. Juno's measurements of Jupiter's magnetic field enabled an estimate of its dynamo radius based …

On the inverse transmission eigenvalue problem with a piecewise $W_2^1$ refractive index
Tao Liu, Kang Lyu, Guangsheng Wei, Chuan-Fu Yang
https://arxiv.org/abs/2509.06520 https:…

On the inverse transmission eigenvalue problem with a piecewise $W_2^1$ refractive index
In this paper, we consider the inverse spectral problem of determining the spherically symmetric refractive index in a bounded spherical region of radius $b$. Instead of the usual case of the refractive index $ρ\in W^2_2$, by using singular Sturm-Liouville theory, we {first} discuss the case when the refractive index $ρ$ is a piecewise $ W^1_2$ function. We prove that if $\int_0^b \sqrt{ρ(r)} dr

Holographic Thermodynamics of Higher-Dimensional AdS Black Holes with CFT Rescaling
Yahya Ladghami, Taoufik Ouali
https://arxiv.org/abs/2510.05700 https://…

Holographic Thermodynamics of Higher-Dimensional AdS Black Holes with CFT Rescaling
In this paper, we study the thermodynamic behavior of charged AdS black holes in higher-dimensional spacetimes within the framework of conformal holographic extended thermodynamics. This formalism is based on a novel AdS/CFT dictionary in which the conformal rescaling factor of the boundary conformal field theory (CFT) is treated as a thermodynamic parameter, while Newton's constant is held fixed and the AdS radius is allowed to vary. We explore how variations in the CFT state, represented by i…

Probing dust torus radius--luminosity relation: An WISE view
Ashutosh Tomar, Suvendu Rakshit, Amit Kumar Mandal, Shivangi Pandey
https://arxiv.org/abs/2510.04517 https://…

Probing dust torus radius--luminosity relation: An WISE view
We present measurements of the dusty torus sizes of 51 active galactic nuclei (AGNs) with a redshift of $z<$ 0.8. Our analysis utilizes about 16 years of optical photometric data of 146 AGNs from various time-domain surveys, including ASAS-SN, CRTS, and ZTF, along with 14 years of infrared data in the $W$1 ($\sim$ 3.4 $μ$m) and $W$2 ($\sim$ 4.6 $μ$m) bands obtained from the Wide-Field Infrared Survey Explorer (WISE). The estimated dust torus size ranges from 1000 to 3000 days, using both the …

An in-depth study of brown dwarfs with TESS
F. Marcadon, A. Pr\v{s}a
https://arxiv.org/abs/2510.05852 https://arxiv.org/pdf/2510.05852

An in-depth study of brown dwarfs with TESS
The existence of a deficit of brown dwarfs (BDs) in close orbit around main-sequence stars is one of the most intriguing questions in stellar physics. This so-called BD desert may result from the transition between two different dominant formation processes occurring for different mass regimes. While the BD mass derived from radial-velocity measurements helps confirm the nature of the analyzed objects, the BD radius obtained from transits is important to better constrain the BD age, as BDs are …

Singularities as Solitons? Quantum Vacuum Architecture of Black Holes
Eren Erberk Erkul
https://arxiv.org/abs/2510.06428 https://arxiv.org/pdf/2510.06428…

Singularities as Solitons? Quantum Vacuum Architecture of Black Holes
We propose that black holes are \emph{soliton-esque} objects, where gravitational collapse is balanced by quantum vacuum dispersion, modeled via \(R+αR^{2}\) gravity. Classical singularities are replaced by oscillating, finite-radius cores, thereby evading static no-go theorems. The event horizon is replaced by the \textit{Lamarina}, a surface of maximum redshift whose surface geometry yields Hawking-like radiation with corrections. The Raychaudhuri equations impose a Dyson-type ceiling on the…

Core or Halo? Two-Fluid Analysis of Dark Matter-Admixed Quarkyonic Stars in the Multi-Messenger Era
Jeet Amrit Pattnaik, D. Dey, M. Bhuyan, R. N. Panda, S. K. Patra
https://arxiv.org/abs/2509.06684

Core or Halo? Two-Fluid Analysis of Dark Matter-Admixed Quarkyonic Stars in the Multi-Messenger Era
For the first time, we explore dark matter (DM) admixed quarkyonic stars (DAQSs) within a two-fluid formalism, where the normal/visible sector is modeled by a quarkyonic equation of state (EOS) in the Effective Relativistic Mean Field (E-RMF) framework and the DM component is treated as a degenerate fermionic gas with scalar and vector self-interactions. Our analysis begins with the mass-radius (M-R) relation, showing that the inclusion of DM enables stellar configurations to reach the mass ran…

$\beta$-Irida-Graphene: A New 2D Carbon Allotrope for Sodium-Ion Battery Anodes
Jos\'e A. S. Laranjeira, Kleuton A. L. Lima, Nicolas F. Martins, Luiz A. Ribeiro Junior, Douglas S. Galv\~ao, Luis A. Cabral, Julio R. Sambrano
https://arxiv.org/abs/2508.04506

$β$-Irida-Graphene: A New 2D Carbon Allotrope for Sodium-Ion Battery Anodes
The quest for sustainable and efficient energy storage has driven the exploration of sodium-ion batteries (SIBs) as promising alternatives to lithium-ion systems. However, the larger ionic radius of sodium poses intrinsic challenges such as slow diffusion and structural strain in conventional electrode materials. As a contribution to addressing these limitations, the \b{eta}-Irida-graphene ($β$-IG) is herein introduced, a novel two-dimensional (2D) carbon allotrope derived from Irida-graphene,…

Spectral extremal problems for the $(p,Q)$-spectral radius of hypergraphs
Jian Zheng, Honghai Li, Li Su
https://arxiv.org/abs/2510.02776 https://arxiv.org/…

Spectral extremal problems for the $(p,Q)$-spectral radius of hypergraphs
Let $Q$ be an $s$-vertex $r$-uniform hypergraph, and let $H$ be an $n$-vertex $r$-uniform hypergraph. Denote by $\mathcal{N}(Q,H)$ the number of isomorphic copies of $Q$ in $H$. For a hereditary family $\mathcal{P}$ of $r$-uniform hypergraphs, define $$π(Q,\mathcal{P}):=\lim\limits_{n\to \infty}\binom{n}{s}^{-1}\max\{\mathcal{N}(Q,H): H\in \mathcal{P}~~\mbox{and}~~|V(H)|=n\}.$$ For $p\geq1$, the $(p,Q)$-spectral radius of $H$ is defined as $$λ^{(p)}(Q,H):=\max_{\|\mathbf{x}\
…

Revisiting the Radius Valley Across Stellar Types: A Transit-Only Analysis of M, K, G, and F Stars with Updated NASA Exoplanet Archive Data
Sukdev Mahapatra
https://arxiv.org/abs/2509.03549

Revisiting the Radius Valley Across Stellar Types: A Transit-Only Analysis of M, K, G, and F Stars with Updated NASA Exoplanet Archive Data
The radius valley -- a deficit of exoplanets between super-Earths and sub-Neptunes -- is a key diagnostic of planet formation and atmospheric evolution. We investigate how the radius valley depends on stellar type by analyzing an updated, transit-only sample of exoplanets from the NASA Exoplanet Archive. Planets are selected with $P < 100$ days and divided by host spectral class (M, K, G, F). We construct weighted radius distributions and apply statistical tests to quantify the valley depth. We…

Optimisation of the vertex detector and measurement of Higgs decays to second-generation quarks at the CEPC
Jialin Li, Liang Hao, Kaili Zhang, Yifan Zhu, Jun Guo, Haijun Yang, Manqi Ruan
https://arxiv.org/abs/2508.04191

Optimisation of the vertex detector and measurement of Higgs decays to second-generation quarks at the CEPC
The vertex detector is crucial for precision measurements of the Higgs boson at the electron-positron Higgs factory. Benchmarked with $H \to c\bar{c}$ and $H \to s\bar{s}$ measurements in the $ν\barνH$ channel, we perform an optimisation study on the inner radius and spatial resolution of the vertex detector using the Jet Origin Identification (JOI) framework, which determines the parton flavor of jets using advanced Artificial Intelligence (AI) algorithm. We observe that, compared to the r…

Wife made pasta with homemade pesto (using basil from our garden) and garlic.
Actually enough garlic, by my standards.
I'm not sure exactly how much she put in, but probably at least one full bulb in the pound of pasta. Maybe more.
It's one of the few things I've ever eaten where there's so much garlic it actually feels slightly spicy.
Apologies to any vampires within a five-mile radius.

AgentZero : Modeling Fear-Based Behavior
Vrinda Malhotra, Jiaman Li, Nandini Pisupati
https://arxiv.org/abs/2510.05185 https://arxiv.org/pdf/2510.05185

AgentZero++: Modeling Fear-Based Behavior
We present AgentZero++, an agent-based model that integrates cognitive, emotional, and social mechanisms to simulate decentralized collective violence in spatially distributed systems. Building on Epstein's Agent\_Zero framework, we extend the original model with eight behavioral enhancements: age-based impulse control; memory-based risk estimation; affect-cognition coupling; endogenous destructive radius; fight-or-flight dynamics; affective homophily; retaliatory damage; and multi-agent coordi…

Gravitational Black Hole Shadow Spectroscopy
Reggie C. Pantig, Ali \"Ovg\"un
https://arxiv.org/abs/2509.05594 https://arxiv.org/pdf/2509.05594

Gravitational Black Hole Shadow Spectroscopy
In this work, we develop a generalized perturbative framework for gravitational shadows in static, spherically symmetric spacetimes. Building upon the recent two-parameter perturbative framework of Kobialko et al. \cite{Kobialko:2024zhc}, this work extends the expansion in particle energy and metric deviation to encompass arbitrary, simultaneous deformations of all metric functions. By relaxing the common restriction of a fixed area radius ($β(r) = r^2$), our formalism applies to a significant…

An improved upper bound on the covering radius of the logarithmic lattice of \mathbb{Q}(\zeta_n)
James Punch
https://arxiv.org/abs/2507.20544 https://arxiv…

An improved upper bound on the covering radius of the logarithmic lattice of \mathbb{Q}(ζ_n)
Let $\mathbb{R}^m$ be endowed with the Euclidean metric. The covering radius of a lattice $Λ\subset \mathbb{R}^m$ is the least distance $r$ such that, given any point of $\mathbb{R}^m$, the distance from that point to $Λ$ is not more than $r$. Lattices can occur via the unit group of the ring of integers in an algebraic number field $\mathbb{K}$, by applying a logarithmic embedding $\mathbb{K}^*\rightarrow \mathbb{R}^m$. In this paper, we examine those lattices which arise from the cyclotomic…

Modified Fronsdal coordinates for maximally extended Schwarzschild spacetime
Andrei Galiautdinov
https://arxiv.org/abs/2510.07287 https://arxiv.org/pdf/251…

Modified Fronsdal coordinates for maximally extended Schwarzschild spacetime
We introduce a coordinate system that complements the Kruskal--Szekeres extension. Like the standard construction, it covers the maximally extended Schwarzschild manifold in its entirety, while offering an additional advantage of expressing the areal radius as an explicit function of the new coordinates. Its main limitation, however, is that radial null geodesics are no longer represented as 45-degree lines in the Kruskal plane, making the causal structure more difficult to interpret. Neverthel…

A spectral condition for Hamilton cycles in tough bipartite graphs
Lianyang Ai, Wenqian Zhang
https://arxiv.org/abs/2508.03778 https://arxiv.org/pdf/2508.0…

A spectral condition for Hamilton cycles in tough bipartite graphs
Let $G$ be a graph. The {\em spectral radius} of $G$ is the largest eigenvalue of its adjacency matrix. For a non-complete bipartite graph $G$ with parts $X$ and $Y$, the {\em bipartite toughness} of $G$ is defined as $t^{B}(G)=\min\left\{\frac{|S|}{c(G-S)}\right\}$, where the minimum is taken over all proper subsets $S\subset X$ (or $S\subset Y$) such that $c(G-S)>1$. In this paper, we give a sharp spectral radius condition for balanced bipartite graphs $G$ with $t^{B}(G)\geq1$ to gu…

Simple analyticity criteria for repulsive multi-body potentials
Tyler Helmuth, Marcus Pappik, Will Perkins
https://arxiv.org/abs/2509.04287 https://arxiv.o…

Simple analyticity criteria for repulsive multi-body potentials
We prove a simple, explicit lower bound on the radius of a zero-free disk for Gibbs point processes defined by finite-range, repulsive multi-body interactions. Our lower bound improves on those previously known, and we demonstrate that it is essentially sharp in the generality with which our arguments apply. The key ingredient is a multi-body generalization of integral identities for point densities of Gibbs point processes in the spirit of earlier work of Michelen and Perkins.

Discovery of giant bubbles in the hot gaseous halo of the massive disk galaxy NGC 6286
Lin He, Zhiyuan Li, Zongnan Li, Rub\'en Garcia-Benito, Yuanqi Liu, Meicun Hou
https://arxiv.org/abs/2509.06470

Discovery of giant bubbles in the hot gaseous halo of the massive disk galaxy NGC 6286
Based on archival Chandra X-ray observation, optical integral-field spectroscopic data and radio interferometric data, we report the discovery of a pair of giant bubbles (with a projected radius ~ 5 kpc) of ionized gas emerging from a highly inclined starburst galaxy NGC 6286, which is undergoing strong tidal interactions with its close neighbor NGC 6285. The bubbles are manifested by extraplanar soft X-ray emission with an X-shaped morphology, which is tightly co-spatial with $\rm Hα$ line em…

From CREX to CEvNS: The Weak Radius of 40Ar
J. Piekarewicz
https://arxiv.org/abs/2509.03645 https://arxiv.org/pdf/2509.03645…

From CREX to CEvNS: The Weak Radius of 40Ar
Despite significant theoretical efforts, the CREX-PREX dilemma remains unresolved, preventing the reliable prediction of neutron (or weak-charge) radii that, besides their intrinsic nuclear-structure interest, often serve to quantify the impact of nuclear uncertainties in searches for new physics. Coherent elastic neutrino-nucleus scattering is a clean and attractive portal to new physics whose sensitivity may be impacted by such nuclear uncertainties. In this paper we use CREX as our main anch…

Seismic test of the mass-radius relationship of hydrogen-atmospheric white dwarf stars
Tianqi Cang, Jiayi Zhang, Jian-Ning Fu, He Zhao, Weikai Zong
https://arxiv.org/abs/2508.03184

Seismic test of the mass-radius relationship of hydrogen-atmospheric white dwarf stars
The pulsation of white dwarfs provides crucial information on stellar parameters for understanding the atmosphere and interior structure of these stars. In this study, we present a comprehensive statistical analysis of known ZZ Ceti stars from historical literature. Our dataset includes stellar parameters and oscillation properties from 339 samples, with 194 of them having undergone asteroseismological analysis. We investigated the empirical instability strip of ZZ Ceti stars and confirmed the …

Notes on Simplifying the Construction of Barabanov Norms
Victor Kozyakin
https://arxiv.org/abs/2509.02230 https://arxiv.org/pdf/2509.02230

Notes on Simplifying the Construction of Barabanov Norms
To answer the question about the growth rate of matrix products, the concepts of joint and generalized spectral radius were introduced in the 1960s. A common tool for finding the joint/generalized spectral radius is the so-called extremal norms and, in particular, the Barabanov norm. The goal of this paper is to try to combine the advantages of different approaches based on the concept of extremality in order to obtain results that are simpler for everyday use. It is shown how the Dranishnikov-…

Nucleon charge radius measurement with low-energy electron scattering
Clement Legris, Rika Danjo, Taiga Goke, Yuki Honda, Kengo Hotta, Rin Kagami, Hiroki Kobayashi, Michael Kohl, Yukie Maeda, Dominique Marchand, Edward Morris, Toshiya Muto, Tetsuya Ohnishi, Shunto Sasaki, Toshimi Suda, Kyo Tsukada, Eric Voutier, Toyohiro Yamauchi, Kosei Yoshimoto
https://

Nucleon charge radius measurement with low-energy electron scattering
The charge radius is one of the most basic characteristics of the nucleons. The proton charge radius is especially of great importance for many applications such as the structure studies of the atomic nuclei, the determination of the Rydberg constant and QED tests. Its determination is thus a hot topic in several physics communities due to inconsistent results using electron scattering, atomic and muonic hydrogen spectroscopy. A new measurement of the proton and deuteron charge radii with low e…

Exploring one-dimensional, binary, radius-2 cellular automata, over cyclic configurations, in terms of their ability to solve decision problems by distributed consensus
Eurico Ruivo, Pedro Paulo Balbi, K\'evin Perrot, Marco Montalva-Medel, Eric Goles
https://arxiv.org/abs/2510.01040

Exploring one-dimensional, binary, radius-2 cellular automata, over cyclic configurations, in terms of their ability to solve decision problems by distributed consensus
Probing the ability of automata networks to solve decision problems has received a continuous attention in the literature, and specially with the automata reaching the answer by distributed consensus, i.e., their all taking on a same state, out of two. In the case of binary automata networks, regardless of the kind of update employed, the networks should display only two possible attractors, the fixed points $0^L$ and $1^L$, for all cyclic configurations of size $L$. A previous investigation in…

Is the high-energy environment of K2-18b special?
S. Rukdee, M. G\"udel, I. Vilovi\'c, K. Poppenh\"ager, S. Boro Saikia, J. Buchner, B. Stelzer, G. Roccetti, J. V. Seidel, V. Burwitz
https://arxiv.org/abs/2510.06939

Is the high-energy environment of K2-18b special?
K2-18b lies near the radius valley that separates super-Earths and sub-Neptunes, marking a key transitional regime in planetary and atmospheric composition. The system offers a valuable opportunity to study how M-dwarf high-energy stellar radiation influences atmospheric stability and the potential for sustaining volatile species, especially important in the context of the upcoming ELT and its ANDES spectrograph. This study characterizes the high-energy environment of K2-18 with X-ray observati…

Resonant Singly Heavy Pentaquarks in the MIT Bag Model: Mass Spectra and Strong Decays
Wen-Nian Liu, Cheng-Jie Wang, Kai-Kai Zhang, Fu-Quan Dou
https://arxiv.org/abs/2510.04813 …

Resonant Singly Heavy Pentaquarks in the MIT Bag Model: Mass Spectra and Strong Decays
Exploring the limits of color interactions in multiquark states is an important topic. Based on the bag confinement picture of hadrons, we find that for singly heavy pentaquarks, the bag confinement radius precisely falls within the range of color interaction limits provided by lattice QCD, approximately 1.17--1.29$\,\text{fm}$. This leads us to believe that singly heavy pentaquark states have the potential to form resonant states. Inspired by singly heavy baryons, we consider the mirror pentaq…

Transformers Discover Molecular Structure Without Graph Priors
Tobias Kreiman, Yutong Bai, Fadi Atieh, Elizabeth Weaver, Eric Qu, Aditi S. Krishnapriyan
https://arxiv.org/abs/2510.02259

Transformers Discover Molecular Structure Without Graph Priors
Graph Neural Networks (GNNs) are the dominant architecture for molecular machine learning, particularly for molecular property prediction and machine learning interatomic potentials (MLIPs). GNNs perform message passing on predefined graphs often induced by a fixed radius cutoff or k-nearest neighbor scheme. While this design aligns with the locality present in many molecular tasks, a hard-coded graph can limit expressivity due to the fixed receptive field and slows down inference with sparse g…

Compact stars with gravitational wave echoes in $f(R,L_{m},T)$ gravitational theory
Meghanil Sinha, S. Surendra Singh
https://arxiv.org/abs/2508.04736 https://

Compact stars with gravitational wave echoes in $f(R,L_{m},T)$ gravitational theory
This work explores the gravitational wave echoes (GWEs) from the compact stellar configurations in the backdrop of $f(R,L_{m},T)$ gravity within static and spherically symmetric framework. Our study has utilized the MIT Bag model and color-favour-locked (CFL) phase equations of state (EoS) for matter description. Mass-radius profiles were determined by solving the hydrostatic equilibrium equations. Model parameter variations were used to assess the configuration stability here. TOV solutions he…

Estimates of the first Dirichlet eigenvalue of graphs
Huiqiu Lin, Lianping Liu, Zhe You, Da Zhao
https://arxiv.org/abs/2510.04557 https://arxiv.org/pdf/251…

Estimates of the first Dirichlet eigenvalue of graphs
Inspired by the Li--Yau eigenvalue-diameter estimates, we investigate lower bounds for the first Dirichlet eigenvalue in terms of the diameter (or inscribed radius) of a graph. Let $G = (V, E)$ be a graph with boundary $B$. Assume that the interior $Ω= V \setminus B$ is connected. Let $r$ be the inscribed radius of $(G, B)$ and $d$ be the maximum degree of $G$. We prove that $$λ_1(G, B) \geq \frac{d - 1}{r d^r},$$ which can be viewed as an analogue of the Lin--Yau bound and the Meng--Lin boun…

Percolation of random compact diamond-shaped systems on the square lattice
Charles S. do Amaral, Mateus G. Soares, Robert M. Ziff
https://arxiv.org/abs/2508.01320 https://

Percolation of random compact diamond-shaped systems on the square lattice
We study site percolation on a square lattice with random compact diamond-shaped neighborhoods. Each site $s$ is connected to others within a neighborhood in the shape of a diamond of radius $r_s$, where $r_s$ is uniformly chosen from the set $\{i, i+1, \ldots, m\}$ with $i \leq m$. The model is analyzed for all values of $i = 0, \ldots, 7$ and $m = i, \ldots, 10$, where $\overline{z}(i,m)$ denotes the average number of neighbors per site and $p_c(i,m)$ is the critical percolation threshold. Fo…

The Berger-Wang formula for order-preserving homogeneous maps on cones
Brian Lins, Aljo\v{s}a Peperko
https://arxiv.org/abs/2509.02787 https://arxiv.org/pd…

The Berger-Wang formula for order-preserving homogeneous maps on cones
We prove that the joint spectral radius and generalized spectral radius are equal for any bounded, equicontinuous family of order-preserving, homogeneous maps on a polyhedral cone. We also consider conditions which guarantee that the semigroup generated by a family of order-preserving, homogeneous maps is bounded when its generalized spectral radius $r(\mathcal{A}) = 1$. Finally, we extend the notions of joint and generalized spectral subradii to the setting of homogeneous maps on wedges.

The impact of the point spread function fitting radius on photometric uncertainty based on the Fisher information matrix
Sebastian Espinosa, Mario L. Vicu\~na, Rene A. Mendez, Jorge F. Silva, Marcos Orchard
https://arxiv.org/abs/2509.20613

The impact of the point spread function fitting radius on photometric uncertainty based on the Fisher information matrix
In point spread function (PSF) photometry, the selection of the fitting aperture radius plays a critical role in determining the precision of flux and background estimations. Traditional methods often rely on maximizing the signal-to-noise ratio (S/N) as a criterion for aperture selection. However, S/N-based approaches do not necessarily provide the optimal precision for joint estimation problems as they do not account for the statistical limits imposed by the Fisher information in the context …

On the eigenvalues of the biharmonic operator on annuli
Davide Buoso, Riccardo Molinarolo
https://arxiv.org/abs/2510.04809 https://arxiv.org/pdf/2510.04809…

On the eigenvalues of the biharmonic operator on annuli
We show that the fundamental tone of the bilaplacian with Dirichlet or Navier boundary conditions on radially symmetric domains is always simple in dimension $N\ge3$. In dimension $N=2$ we show that it is simple if the inner radius is big enough.

The covering radius of Butson Hadamard codes for the homogeneous metric
Xingxing Xu, Minjia Shi, Patrick Sole
https://arxiv.org/abs/2508.12859 https://arxi…

The covering radius of Butson Hadamard codes for the homogeneous metric
Butson matrices are complex Hadamard matrices with entries in the complex roots of unity of given order. There is an interesting code in phase space related to this matrix (Armario et al. 2023). We study the covering radius of Butson Hadamard codes for the homogeneous metric, a metric defined uniquely, up to scaling, for a commutative ring alphabet that is Quasi Frobenius. An upper bound is derived by an orthogonal array argument. A lower bound relies on the existence of bent sequences in the s…

Theoretical estimate and characteristics of electro-vortex flows in cylindrical electrodes
Swapnil Soni, Avishek Ranjan
https://arxiv.org/abs/2508.02297 https://

Theoretical estimate and characteristics of electro-vortex flows in cylindrical electrodes
Electro-vortex flows (EVF) arise in conducting fluids due to diverging current lines and the non-conservative Lorentz force. They are typically characterized by the $S$ parameter, defined as $S=μ_0 I^2/4π^2 ρν^2$, where it is known that $Re \sim \sqrt{S}$ for large currents. However, the strength of the EVF in a confined cylindrical domain with a co-axially placed current collector (CC) depends also on the ratio of the CC radius to the cylinder radius, $K=r_0/R$, in addition to the current …

Constraining the Milky Way dark matter halo with LMC-induced reflex motion
Rashid Yaaqib, Michael Petersen, Jorge Pe\~narrubia
https://arxiv.org/abs/2508.04781 https://

Constraining the Milky Way dark matter halo with LMC-induced reflex motion
Modelling perturbations of the Milky Way (MW) halo induced by the infall of the Large Magellanic Cloud (LMC) offers new avenues to constrain the dark matter (DM) distribution in our Galaxy. A key observable is the reflex motion of the MW disc with respect to the halo induced by the LMC's infall, which imprints a velocity dipole on kinematics of halo stars. Here we investigate how the dipole varies with Galactocentric radius, and study the sensitivity of the reflex motion signal to different DM …

Quintessence-Chameleon transitions in anisotropic Kiselev model of neutron stars
M. V. Pradosh Keshav (Christ University, Bangalore), V. Jithesh (Christ University, Bangalore), Kenath Arun (Christ University, Bangalore)
https://arxiv.org/abs/2508.04744

Quintessence-Chameleon transitions in anisotropic Kiselev model of neutron stars
We investigate a chameleon scalar field dynamically interacting with a Kiselev-type metric, where the static anisotropic fluid part of the metric is replaced by a density-dependent scalar field non-minimally coupled to curvature. This construction enables a transition from screened behavior in high-density regions-where the scalar acquires an effective mass m_ϕ\proptoρ^1/2-to unscreened quintessence dynamics at large scales, characterized by a critical screening radius r_\rm crit\propto m_ϕ^…

A note on the spectral radius and $[a,b]$-factor of graphs
Dandan Fan, Huiqui Lin, Yinfen Zhu
https://arxiv.org/abs/2509.00769 https://arxiv.org/pdf/2509.0…

A note on the spectral radius and $[a,b]$-factor of graphs
The investigation of eigenvalue conditions for the existence of an $[a,b]$-factor originates in the work of Brouwer and Haemers (2005) on perfect matchings. In the decades since, spectral extremal problems related to $[a,b]$-factors have attracted considerable attention. In this paper, we establish a spectral radius condition that ensures the existence of an $[a,b]$-factor in a graph $G$ with minimum degree $δ(G) \geq a$, where $b > a \geq 1$. This result resolves a problem posed by Hao and Li…

Asymptotic behavior of the spectral radius of locally constant strongly irreducible cocycles
Nicolas Martinez Ramos
https://arxiv.org/abs/2507.19624 https://

Asymptotic behavior of the spectral radius of locally constant strongly irreducible cocycles
We establish some conditions under which $\text{GL}(d,\mathbb{R})$-valued cocycles over a subshift of finite type, equipped with an equilibrium state, exhibit exponential asymptotics for the spectral radius. Specifically, we show that the exponential growth rate of the spectral radius converges to the top Lyapunov exponent of the cocycle. This result provides a partial answer to a question posed by Aoun and Sert in \cite{aoun}. Our approach relies on large deviation estimates for linear cocycle…

Prospects for compact hexaquarks under the limitation imposed by quark confinement
Wen-Xuan Zhang, Wen-Nian Liu, Duojie Jia
https://arxiv.org/abs/2510.04103 https://

Prospects for compact hexaquarks under the limitation imposed by quark confinement
The limitation of flavor constituents for compact multiquarks is crucial for understanding the strong interaction at the low energy scale. Utilizing the MIT bag model that incorporates perturbative interactions and confinement energy $E_{\rm CON}$, we derive a critical bag radius $R_c=5.61\,$GeV$^{-1}$ from the condition $E_{\rm CON} < 0$ at zero temperature and zero baryon density, which aligns with the string-breaking distance of 1.2--1.4$\,$fm. Applying this framework to 6-, 7-, and 8-quark …

Effect of Tube Radius on the Adsorption of Chlorothalonil on Single-Walled Carbon and Boron Nitride Nanotube Surfaces: A Theoretical Study for Environmental Remediation
Francisco Gleidson de S. Ferreira, Caio V. C. Ribeiro da Silva, Silvete Guerini, Kleuton A. L. Lima, Douglas Soares Galv\~ao, Jos\'e Milton Elias de Matos, Alexandre Araujo de Souza
https://…

Effect of Tube Radius on the Adsorption of Chlorothalonil on Single-Walled Carbon and Boron Nitride Nanotube Surfaces: A Theoretical Study for Environmental Remediation
We investigated the interaction of the pesticide chlorothalonil (CLT) with single-walled carbon nanotubes (CNTs) and boron nitride nanotubes (BNNTs) using density functional theory (DFT) with the SIESTA code. Structural, energetic, and electronic analyses were used to characterize adsorption on nanotube surfaces. The adsorption energy becomes more favorable as the tube radius increases, consistent with enhanced pi-pi stacking on less curved surfaces. Both CNTs and BNNTs physisorb CLT; however, …

Evolution of the Physical Properties of the Most Massive Galaxies in Clusters and their Protohalos
Qingyang Li, Xiaohu Yang, Antonios Katsianis, Paola Popesso, Ilaria Marini, Y. Sophia Dai, Chengze Liu, Yipeng Jing, Jia-Sheng Huang, Marcin Sawicki
https://arxiv.org/abs/2509.05637

Evolution of the Physical Properties of the Most Massive Galaxies in Clusters and their Protohalos
We investigated the evolution of the physical properties of the brightest galaxies in clusters and their protohalos from $z = 4$ to $z = 0$. Galaxy clusters and groups are identified using a halo-based group finder applied to the COSMOS2020 galaxy catalog. We construct evolution chains from low redshift clusters to higher redshift groups via the abundance matching method. The region of protohalos corresponding to clusters is defined on the basis of a characteristic radius. Our analysis encompas…

This is disappointing.
Unfortunately, the ICEBlock app is activism theater
https://micahflee.com/unfortunately-the-iceblock-app-is-activism-theater/

Unfortunately, the ICEBlock app is activism theater
At this summer's HOPE conference, Joshua Aaron spoke about ICEBlock, his iPhone app that allows users to anonymously report ICE sightings within a 5 mile radius, and to get notifications when others report ICE sightings near them. You can see the full talk, and the lively/infuriating Q&A, here,

Slowly Rotating Relativistic Stars: VII. Gravitational Radiation from the Quasi-Radial Modes
James B. Hartle (University of California Santa Barbara), Kip S. Thorne (California Institute of Technology)
https://arxiv.org/abs/2509.05436

Slowly Rotating Relativistic Stars: VII. Gravitational Radiation from the Quasi-Radial Modes
When a relativistic star rotates slowly and rigidly, centrifugal forces flatten it slightly, thereby catalyzing a small admixture of quadrupolar vibration into its radial modes and a damping of the resulting quasi-radial modes. The damping rate $1/τ$ of each quasi-radial mode divided by its frequency $σ^{(0)}$ is given by ${(1/τ) / σ^{(0)} }= β(σ^{(0)})^3 Ω^4 R^8/M \;, $where $Ω$, $R$ and $M$ are the angular velocity, radius and mass of the star, and $β$ is a dimensionless number that …

Improved Upper Bounds for Numerical Radius Inequalities of Operator Matrices and Their Applications
M. H. M. Rashid
https://arxiv.org/abs/2508.00845 https://

Improved Upper Bounds for Numerical Radius Inequalities of Operator Matrices and Their Applications
This study presents new upper bounds for the numerical radii of operator matrices, with a focus on $n \times n$ and $2 \times 2$ block matrices acting on Hilbert space direct sums. By employing techniques such as the Hölder-McCarthy inequality, Jensen's inequality, Bohr's inequality, and extensions of the Buzano inequality, we derive improved estimates that refine classical results by Kittaneh, El-Haddad, Dragomir, Buzano, and others. Our main contributions include bounds for general operator …

Effective Radius of a Discrete Moving Polymer
Jiaming Chen
https://arxiv.org/abs/2507.22248 https://arxiv.org/pdf/2507.22248…

Effective Radius of a Discrete Moving Polymer
We present a discrete space-time stochastic partial differential equation (SPDE) model to describe the dynamics of a weakly self-avoiding polymer with intrinsic length $J$. By introducing a penalty factor tailored to the discrete setting, we establish that the polymer's root mean squared radius scales linearly with $J$. This scaling behavior differs from the law derived by Mueller and Neuman \cite{mueller2022scaling} in the continuous framework, highlighting both the distinct nature of the disc…

An Analysis of the Radius Gap in a Sample of Kepler, K2 and TESS exoplanets orbiting M Dwarf Stars
F\'abio Wanderley, Katia Cunha, Verne V. Smith, Diogo Souto, Ilaria Pascucci, Aida Behmard, Carlos Allende Prieto, Rachael L. Beaton, Dmitry Bizyaev, Simone Daflon, Sten Hasselquist, Steve Howell, Steven R. Majewski, Marc Pinsonneault
https://

An Analysis of the Radius Gap in a Sample of Kepler, K2 and TESS exoplanets orbiting M Dwarf Stars
Planetary radii are derived for 218 exoplanets orbiting 161 M dwarf stars. Stellar radii are based on an analysis of APOGEE high-resolution near-IR spectra for a subsample of the M-dwarfs; these results are used to define a stellar radius-M$_{\rm K_{\rm s}}$ calibration that is applied to the sample of M-dwarf planet hosts. The planetary radius distribution displays a gap over R$_{\rm p}$$\sim$1.6-2.0 R$_{\oplus}$, bordered by two peaks at R$_{\rm p}$$\sim$1.2-1.6 R$_{\oplus}$ (super-Earths) an…

Rubin Data Preview 1: Extending the View of Unresolved Binary Stars in 47 Tucanae
Giacomo Cordoni, Luca Casagrande, Helmut Jerjen
https://arxiv.org/abs/2509.04054 https://

Rubin Data Preview 1: Extending the View of Unresolved Binary Stars in 47 Tucanae
Until now, the study of unresolved main sequence binary stars in globular clusters has been possible almost exclusively in their central regions with deep Hubble Space Telescope (HST) observations. We present the first detection of unresolved main-sequence binary stars in the outer field of 47 Tucanae using Rubin Observatory's Data Preview 1 (DP1). Our analysis exploits deep $i$ vs. $g-i$ colour-magnitude diagrams beyond the cluster's half-light radius, reaching almost to the tidal radius. The …

Stabilizability and lower spectral radius for linear switched systems with singular matrices
Carl P. Dettmann, Chenmiao Zhang
https://arxiv.org/abs/2509.17799 https://

Stabilizability and lower spectral radius for linear switched systems with singular matrices
We investigate the stabilizability of linear discrete-time switched systems with singular matrices, focusing on the spectral radius in this context. A new lower bound of the stabilizability radius is proposed, which is applicable to any matrix set. Based on this lower bound, more relationships between the stabilizability radius and joint spectral subradius are established. Detailed analysis of the stabilizability radius of a special kind of two-dimensional switched system, consisting of a singu…

Mapping the Nearest Ancient Sloshing Cold Front in the Sky with XMM-Newton
Sheng-Chieh Lin, Yuanyuan Su, Iraj Vaezzadeh, William Forman, Elke Roediger, Charles Romero, Paul Nulsen, Scott W. Randall, John ZuHone, Ralph Kraft, Christine Jones
https://arxiv.org/abs/2510.03150

Mapping the Nearest Ancient Sloshing Cold Front in the Sky with XMM-Newton
The Virgo Cluster is the nearest cool core cluster that features two well-studied sloshing cold fronts at radii of $r \approx 30$ kpc and $r \approx 90$ kpc, respectively. In this work, we present results of XMM-Newton mosaic observations of a third, southwestern, cold front at a radius of $r \approx 250$ kpc, originally discovered with Suzaku. All three cold fronts are likely to be parts of an enormous swirling pattern, rooted in the core. The comparison with a numerical simulation of a binary…

Spectral radius of simplicial complexes without holes
Yi-Zheng Fan, Chuan-Ming She
https://arxiv.org/abs/2507.22518 https://arxiv.org/pdf/2507.22518…

Spectral radius of simplicial complexes without holes
The Turán problem for hypergraphs and its spectral version is a central and challenging topic in extremal combinatorics. In this paper, we view hypergraphs from the perspective of simplicial complexes, and investigate the spectral version of Turán problem for simplicial complexes. We characterize the simplicial complex that maximizes the signless Laplacian spectral radius among all hole-free simplicial complexes, and establish an upper bound on the spectral radius for simplicial complexes wit…

Some results on spectra and certain norms
Danielle Witt
https://arxiv.org/abs/2510.04199 https://arxiv.org/pdf/2510.04199

Some results on spectra and certain norms
Given the norms of powers $(\lVert x^n\rVert)_{n\geq 0}$ of a Banach algebra element $x$, the largest possible value of the minimum modulus on the spectrum of $x$ is determined. It is also shown that, given a Banach algebra element $x$ and a compact set $K\subset\mathbb{C}$ with maximum modulus no more than the spectral radius of $x$, there exists a Banach algebra element $y$ with $\lVert y^n\rVert=\lVert x^n\rVert$ for all $n\geq 0$ and spectrum equal to the union of the spectrum of $x$ and $K…

The Radius, Composition, Albedo, and Absolute Magnitude of Planet Nine Based on Exoplanets with Teq less than 600 K and the Planet Nine Reference Population 3.0
David G. Russell, Terry L. White
https://arxiv.org/abs/2507.22297

The Radius, Composition, Albedo, and Absolute Magnitude of Planet Nine Based on Exoplanets with Teq less than 600 K and the Planet Nine Reference Population 3.0
Evidence suggests the existence of a large planet in the outer Solar System, Planet Nine, with a predicted mass of 6.6 +2.6 / -1.7 Earth masses (Brown et al., 2024). Based on mass radius composition models, planet formation theory, and confirmed exoplanets with low mass and radius uncertainty and equilibrium temperature less than 600 K, we determine the most likely composition for Planet Nine is a mini-Neptune with a radius in the range 2.0 to 2.6 Earth radii and a H-He envelope fraction in the…

Power corrections to the production of a prompt photon in association with a jet in the $N$-jettiness slicing scheme at NLO QCD
Prem Agarwal, Kirill Melnikov, Ivan Pedron
https://arxiv.org/abs/2510.03097

Power corrections to the production of a prompt photon in association with a jet in the $N$-jettiness slicing scheme at NLO QCD
We compute the next-to-leading-power corrections in the $N$-jettiness variable to the production of a prompt photon and a jet at next-to-leading order in perturbative QCD in the $q \bar q$ annihilation channel. We employ the $k_\perp$ jet algorithm and assume that the $N$-jettiness value divided by the jet transverse momentum is the smallest parameter in the problem; in particular it should be small compared to the jet radius $R$.

Investigating the Jet Width Profile of CTA 102 with Very Long Baseline Interferometry at Parsec Scales
ZhanHao Ng, Juan Carlos Algaba, Zamri Zainal Abidin
https://arxiv.org/abs/2508.03044

Investigating the Jet Width Profile of CTA 102 with Very Long Baseline Interferometry at Parsec Scales
Active Galactic Nucleus jets have long be thought to exhibit a conical jet shape, but recently, several jets were found to have a transition from parabolic to conical structure. As more sources are investigated, this collimation profile appears to represent a common paradigm. Previous works suggest that the Bondi radius may serve as an indicator of the transition location, although discrepancies have been observed in some sources. To explore this further, we selected CTA 102 for which existing …

Capillary currents and viscous droplet spreading
David Darrow, Lucas Warwaruk, John W. M. Bush
https://arxiv.org/abs/2508.01053 https://arxiv.org/pdf/2508.…

Capillary currents and viscous droplet spreading
We present the results of a combined experimental and theoretical study of the spreading of viscous droplets over rough and smooth substrates. First, we experimentally investigate the wetting of a roughened glass surface by a viscous droplet of silicone oil, wide and shallow relative to the capillary length $\ell_c$. The radius of the droplet grows according to a $R_\mathrm{drop}\sim t^{1/8}$ scaling reminiscent of gravity currents (Lopez, 1976; Voinov, 1999). The droplet is preceded by a mesos…

Eigenvalue Bounds for Random Matrices via Zerofreeness
Sidhanth Mohanty, Amit Rajaraman
https://arxiv.org/abs/2509.25471 https://arxiv.org/pdf/2509.25471…

Eigenvalue Bounds for Random Matrices via Zerofreeness
We introduce a new technique to prove bounds for the spectral radius of a random matrix, based on using Jensen's formula to establish the zerofreeness of the associated characteristic polynomial in a region of the complex plane. Our techniques are entirely non-asymptotic, and we instantiate it in three settings: (i) The spectral radius of non-asymptotic Girko matrices -- these are asymmetric matrices $\mathbf{M} \in \mathbb{C}^{n \times n}$ whose entries are independent and satisfy $\mathbb{E…

Spectral radius and homeomorphically irreducible spanning trees of graphs
Bingqian Gao, Huiqing Liu, Jing Zhao
https://arxiv.org/abs/2509.02021 https://arx…

Spectral radius and homeomorphically irreducible spanning trees of graphs
For a connected graph $G$, a spanning tree $T$ of $G$ is called a homeomorphically irreducible spanning tree (HIST) if $T$ has no vertices of degree 2. Albertson {\em et al.} proved that it is $NP$-complete to decide whether a graph contains a HIST. In this paper, we provide some spectral conditions that guarantee the existence of a HIST in a connected graph. Furthermore, we also present some sufficient conditions in terms of the order of a graph $G$ to ensure the existence of a HIST in $G$.

Kullback-Leibler Divergence as a Measure of Irreversible Information Loss Near Black Hole Horizons
Tatsuaki Tsuruyama
https://arxiv.org/abs/2508.04348 https://

Kullback-Leibler Divergence as a Measure of Irreversible Information Loss Near Black Hole Horizons
We present a unified theoretical framework that integrates information theory, thermodynamics, and general relativity to analyze the fundamental limit of decoding time-encoded signals in curved spacetime. In particular, we introduce the Kullback-Leibler divergence (KLD) as a quantitative measure of the mismatch between the transmitted and received symbol distributions induced by gravitational time dilation. Using a minimal communication model, we derive the critical radius at which information …

The X-ray Variability and Luminosity Function of High Mass X-ray Binaries in the Dwarf Starburst Galaxy IC 10
Breanna A. Binder, Rosalie Lazarus, Mina Thoresen, Silas Laycock, Sayantan Bhattacharya
https://arxiv.org/abs/2508.02876

The X-ray Variability and Luminosity Function of High Mass X-ray Binaries in the Dwarf Starburst Galaxy IC 10
We present an analysis of $\sim$235 ks of Chandra observations obtained over $\sim$19 years of the nearby dwarf starburst galaxy IC 10 in order to study the X-ray variability and X-ray luminosity function (XLF) of its X-ray binary (XRB) population. We identify 23 likely XRBs within the 2MASS $K_S$ isophotal radius and find the distributions of their dynamic ranges and duty cycles are consistent with a young, high-mass XRB population dominated by supergiant (sg)-fed systems, consistent with prev…

Searching for Ultra-light Dark Matter in Spatial Correlations of White Dwarf Structure
Nicole R. Crumpler, Nadia L. Zakamska, Gautham Adamane Pallathadka, Kareem El-Badry
https://arxiv.org/abs/2510.00271

Searching for Ultra-light Dark Matter in Spatial Correlations of White Dwarf Structure
If dark matter is ultra-light and has certain Standard Model interactions, it can change the mass-radius relation of white dwarf stars. The coherence length of ultra-light dark matter imparts spatial correlations in deviations from the canonical mass-radius relation, and thus white dwarfs can be used to reconstruct the coherence length, or equivalently the particle mass, of the dark matter field. We simulate the observability of such spatial correlations accounting for realistic complications l…

Bounds on the propagation radius in power domination
Imran Allie, Brandon du Preez, Dean Reagon, Adriana Roux
https://arxiv.org/abs/2510.02211 https://arxi…

Bounds on the propagation radius in power domination
Let $G$ be a graph and let $S \subseteq V(G)$. It is said that $S$ \textit{dominates} $N[S]$. We say that $S$ \textit{monitors} vertices of $G$ as follows. Initially, all dominated vertices are monitored. If there exists a vertex $v \in G$ which is not monitored, but has all but one of its neighbours monitored, then $v$ becomes monitored itself. This step is called a \textit{propagation} step and is repeated until the process terminates. The process terminates when the there are no unmonitored …

Computing $c$- and $a$-functions from entanglement
Konstantinos Boutivas, Dimitrios Katsinis, Georgios Pastras, Nikolaos Tetradis
https://arxiv.org/abs/2509.03259 https://

Computing $c$- and $a$-functions from entanglement
We confirm the direct connection between entanglement entropy and the notion of irreversibility in the renormalization-group flow in the context of a simple theory for which a calculation from first principles is feasible. The change of the entanglement entropy for a spherical entangling surface as its radius grows from zero to infinity corresponds to the flow from the UV to the IR. Through analytical and numerical means, we compute the entanglement entropy for a free massive scalar theory, mak…

Scattering number and $\tau$-toughness in graphs involving $A_\alpha$-spectral radius
Caili Jia, Yong Lu
https://arxiv.org/abs/2509.01050 https://arxiv.org…

Scattering number and $τ$-toughness in graphs involving $A_α$-spectral radius
The scattering number $s(G)$ of graph $G=(V,E)$ is defined as $s(G)$=max\big\{$c(G-S)-|S|$\big\}, where the maximum is taken over all proper subsets $S\subseteq V(G)$, and $c(G-S)$ denotes the number of components of $G-S$. In 1988, Enomoto introduced a variation of toughness $τ(G)$ of a graph $G$, which is defined by $τ(G)$=min\big\{$\frac{|S|}{c(G-S)-1}$, $S\subseteq V(G)$ and $c(G-S)>1$\big\}. Both the scattering number and toughness are used to characterize the invulne…

Modeling Emission-Line Surface Brightness in a Multiphase Galactic Wind: An O VI Case Study
Zirui Chen, Zixuan Peng, Kate H. R. Rubin, Timothy M. Heckman, Matthew J. Hayes, Yakov Faerman, Crystal L. Martin, S. Peng Oh, Drummond B. Fielding
https://arxiv.org/abs/2510.02443

Modeling Emission-Line Surface Brightness in a Multiphase Galactic Wind: An O VI Case Study
We present a fast and robust analytic framework for predicting surface brightness (SB) of emission lines in galactic winds as a function of radius up to $\sim 100$ kpc out in the circum-galactic medium. We model multi-phase structure in galactic winds by capturing emission from both the volume-filling hot phase (T $\sim 10^{6-7}$ K) and turbulent radiative mixing layers that host intermediate temperature gas at the boundaries of cold clouds (T $\sim 10^4$ K). Our multi-phase framework makes sig…

Understanding the Origins of Super-Puff Planets: A New Mass-Loss Regime Coupled to Planetary Evolution
Yao Tang, Jonathan J. Fortney, Ruth Murray-Clay, Madelyne Broome
https://arxiv.org/abs/2510.02201 …

Understanding the Origins of Super-Puff Planets: A New Mass-Loss Regime Coupled to Planetary Evolution
Super-puffs are a class of low-mass, large-radius planets that have challenged planet formation and evolution models. Their high inferred H/He mass fractions, required to explain their physical sizes, would lead to rapid atmospheric escape, raising questions about their long-term retention. Recent modeling work indicates that low-mass planets typically require 50\% less H/He mass to match their observed radius, due to significant roles of the radiative atmosphere and interior heating from the r…

Revisiting symbiotic binaries with interferometry: II. New PIONIER data
Henri M. J. Boffin, Jaroslav Merc
https://arxiv.org/abs/2508.01304 https://arxiv.or…

Revisiting symbiotic binaries with interferometry: II. New PIONIER data
Symbiotic stars, which generally comprise a red giant and an accreting white dwarf, are excellent laboratories to understand mass transfer in wide binaries, with application to a wide family of systems. One of the fundamental questions is how mass is transferred from the red giant to the white dwarf. We use interferometric measurements made with the VLTI/PIONIER instrument, combined with Gaia data, to measure the radius of the giant in seven symbiotic systems. We further place the giants in the…

PSR J0614-3329: A NICER case for Strange Quark Stars
Swarnim Shirke, Rajesh Maiti, Debarati Chatterjee
https://arxiv.org/abs/2508.02652 https://arxiv.org/p…

PSR J0614-3329: A NICER case for Strange Quark Stars
Precise measurements of neutron star masses and radii by the NICER mission impose important constraints on the nuclear equation of state. The most recent NICER measurement of PSR J0614-3329 reported an equatorial radius of $R_{eq} = 10.29^{+1.01}_{-0.86}$ km for a mass of $M = 1.44^{+0.06}_{-0.07} M_{\odot}$. Considering all the NICER measurements to date, we demonstrate using Bayesian hypothesis ranking that strange quark stars are preferred over all the physically motivated models of neutron …

Spectral extremal problem of the $p$th power of cycles
Xinhui Duan, Lu Lu
https://arxiv.org/abs/2508.03746 https://arxiv.org/pdf/2508.03746

Spectral extremal problem of the $p$th power of cycles
For a cycle $C_k$ on $k$ vertices, its $p$-th power, denoted $C_k^p$, is the graph obtained by adding edges between all pairs of vertices at distance at most $p$ in $C_k$. Let $\ex(n, F)$ and $\spex(n, F)$ denote the maximum possible number of edges and the maximum possible spectral radius, respectively, among all $n$-vertex $F$-free graphs. In this paper, we determine precisely the unique extremal graph achieving $\ex(n, C_k^p)$ and $\spex(n, C_k^p)$ for sufficiently large $n$.

Corotating Interaction Regions (CIRs): impacts with exoplanets
Rose Waugh, Moira Jardine
https://arxiv.org/abs/2508.01267 https://arxiv.org/pdf/2508.01267

Corotating Interaction Regions (CIRs): impacts with exoplanets
Corotating interaction regions (CIRs) are compressions that form in stellar winds when streams of different speeds collide. They form an Archimedean spiral around the star and can compress any exoplanetary magnetospheres they impact. They may also steepen into shocks capable of accelerating particles to high energies. We model the frequency and strength of these CIRS for stars of spectral types F-M. We show that the minimum radius, $r_{CIR}=Δϕu_{slow}/Ω$, at which CIRs form varies strongly w…

CHEMOUT: CHEMical complexity in star-forming regions of the OUTer Galaxy. V. Chemical composition gradients as a function of the Galactocentric radius
D. Gigli, F. Fontani, L. Colzi, G. Vermari\"en, S. Viti, V. M. Rivilla, A. S\'anchez-Monge
https://arxiv.org/abs/2509.26556

CHEMOUT: CHEMical complexity in star-forming regions of the OUTer Galaxy. V. Chemical composition gradients as a function of the Galactocentric radius
The outer Galaxy is characterized by a lower metallicity than regions near the Sun, suggesting differences in the formation and survival of molecules in star-forming regions. To understand chemical evolution across the Milky Way, deriving molecular abundances in star-forming regions in the outer Galaxy is essential for refining models of sub-Solar metallicity environments. We analyzed IRAM 30m observations at 3 and 2 mm toward 35 sources at Galactocentric distances of 9$-$24 kpc, within the "CH…

Shadow and Quasi-Normal Modes of Schwarzschild-Hernquist Black Hole
Xing-Hui Feng, Guang-Yu Zhang
https://arxiv.org/abs/2509.04001 https://arxiv.org/pdf/25…

Shadow and Quasi-Normal Modes of Schwarzschild-Hernquist Black Hole
In this paper we study the shadow and quasi-normal modes (QNMs) of a black hole (BH) surrounded by a dark matter halo with Hernquist-type density distribution, which was reported in Ref. \cite{Cardoso:2021wlq}. In astrophysical scenarios, we find that the shadow radius enlarges as the compactness of halo increases. Therefore, we obtain an upper bound for the compactness ${\cal C}\le0.092$ with the Event Horizon Telescope (EHT) observations. We calculate axial gravitational QNMs of the galactic …

Spectral Tur\'an-type problems for the $\alpha$-spectral radius of hypergraphs with degree stability
Jian Zheng, Honghai Li, Li Su
https://arxiv.org/abs/2509.24354 https://

Spectral Turán-type problems for the $α$-spectral radius of hypergraphs with degree stability
An $r$-pattern $P$ is defined as an ordered pair $P=([l],E)$, where $l$ is a positive integer and $E$ is a set of $r$-multisets with elements from $[l]$. An $r$-graph $H$ is said to be $P$-colorable if there is a homomorphism $ϕ$: $V(H)\rightarrow [l]$ such that the $r$-multiset $\{ϕ(v_{1}),\ldots,ϕ(v_{r})\}$ is in $E$ for every edge $\{v_{1},\ldots,v_{r}\}\in E(H)$. Let $Col(P)$ denote the family of all $P$-colorable $r$-graphs. This paper establishes spectral extremal results for $α$-spec…

A JWST/MIRI view of k Andromedae b: Refining its mass, age, and physical parameters
N. Godoy, E. Choquet, E. Serabyn, M. Malin, P. Tremblin, C. Danielski, P. O. Lagage, A. Boccaletti, B. Charnay, M. E. Ressler
https://arxiv.org/abs/2509.03624

A JWST/MIRI view of k Andromedae b: Refining its mass, age, and physical parameters
Context. kAndb is a substellar companion near the planet-brown dwarf boundary, orbiting a B9IV star at 50-100 au. Estimates of its age and mass vary, fueling a decade-long debate. Atmospheric parameters (Teff 1650-2050 K, log(g) 3.5-5.5) remain poorly constrained due to model differences and heterogeneous datasets. Aims. We refine the characterization of kAndb using mid-infrared data to capture its bolometric emission. Combined with NIR measurements, we constrain Teff, log(g), and radius to red…

Correction to Hawking radiation in non-singular gravitational collapse
Hassan Mehmood
https://arxiv.org/abs/2509.03723 https://arxiv.org/pdf/2509.03723

Correction to Hawking radiation in non-singular gravitational collapse
Recent studies have shown that quantum gravity introduces important corrections to the process of spherically symmetric gravitational collapse expected from general relativity. In particular, instead of falling into a central singularity, the collapsing body undergoes a bounce and eventually exits its Schwarzschild radius, and this entire process of collapse and rebound can occur in a single asymptotic region. In this paper, particle creation during such non-singular gravitational collapse is s…

Estimate of Current Mass of the Large Magellanic Cloud from the Orphan-Chenab Tidal Stream
Hiroka T. Warren, Heidi Jo Newberg, Autumn G. Guffey, JiaZhao Lin, Eric J. Mendelsohn, Kevin Roux
https://arxiv.org/abs/2508.01086

Estimate of Current Mass of the Large Magellanic Cloud from the Orphan-Chenab Tidal Stream
By fitting the tilt in the path of the Orphan-Chenab Stream (OCS), we conclude that the current mass of the Large Magellanic Cloud (LMC) within 30 kpc is $4.7$ - $5.1 \times 10^{10}$ M$_\odot$. We note that the tidal radius of the LMC of this mass is 16.9 kpc, indicating that our measured mass approximates the current bound mass of the LMC. Previous measurements of the LMC mass based on fitting the observed path of the OCS through the Milky Way (MW) halo reported the total mass of the LMC. We s…

Classification of global structures of evaporating regular black holes with infinite periods of time
Kensuke Sueto, Hirotaka Yoshino
https://arxiv.org/abs/2508.21315 https://

Classification of global structures of evaporating regular black holes with infinite periods of time
We carry out model independent analyses for global structures of spherically symmetric regular black holes that evaporate and approach the extremal state spending infinite periods of time due to Hawking radiation. We assume the radius of the outer apparent horizon (outer AH) to be a decreasing function of ingoing null coordinate, and consider the three cases, Cases 1, 2, and 3, where the radius of the inner AH is a constant, increases, and decreases, respectively. A complete classification …

Extremal distance spectral radius of graphs with $h$-extra $r$-component connectivity
Daoxia Zhang, Dan Li, Wenxiu Ding
https://arxiv.org/abs/2509.22538 https://

Extremal distance spectral radius of graphs with $h$-extra $r$-component connectivity
For two integers $r\geq 2$ and $h\geq 0$, the $h$-extra $r$-component connectivity of a graph $G$, denoted by $cκ_{r}^{h}$, is defined as the minimum number of vertices whose removal produces a disconnected graph with at least $r$ components, where each component contains at least $h+1$ vertices. Let $\mathcal{G}_{n,δ}^{cκ_{r}^{h}}$ represent the set of graphs of order $n$ with minimum degree $δ$ and $h$-extra $r$-component connectivity $cκ_{r}^{h}$. Hu, Lin, and Zhang [\textit{Discrete Ma…

Horizonless star based on regular black hole with finite radius and its observational signatures
M. F. Fauzi, B. N. Jayawiguna, H. S. Ramadhan, A. Sulaksono
https://arxiv.org/abs/2508.18072

Horizonless star based on regular black hole with finite radius and its observational signatures
The horizonless configuration of regular black holes has recently attracted attention as a model for ultracompact stars. In this paper, we propose a new class of regular black hole models sourced by a de Sitter vacuum with a finite radius. We focus on studying its horizonless configuration, which is modified into an anisotropic gravastar by proposing an ansatz of equation of states. We confirm that an anisotropic gravastar approaching horizon formation must violate the dominant energy condition…

Effective Free Energy Landscapes and Hawking-Page Transitions
Choon-Lin Ho
https://arxiv.org/abs/2509.25039 https://arxiv.org/pdf/2509.25039

Effective Free Energy Landscapes and Hawking-Page Transitions
A recent interesting development on the dynamics of black hole phase transitions, the Hawking-Page transition, has been the so-called Gibbs free energy landscape approach. In this formalism, it is assumed that there exists a canonical ensemble of a series of black hole spacetimes with arbitrary horizon radius at a given ensemble temperature. An off-shell Gibbs free energy is defined for every spacetime state in the ensemble, with the horizon radius treated as the order parameter. The minima (ma…

Reinforcement learning for graph theory, Parallelizing Wagner's approach
Alix Bouffard, Jane Breen
https://arxiv.org/abs/2509.01607 https://arxiv.org/p…

Reinforcement learning for graph theory, Parallelizing Wagner's approach
Our work applies reinforcement learning to construct counterexamples concerning conjectured bounds on the spectral radius of the Laplacian matrix of a graph. We expand upon the re-implementation of Wagner's approach by Stevanovic et al. with the ability to train numerous unique models simultaneously and a novel redefining of the action space to adjust the influence of the current local optimum on the learning process.