Tootfinder

Description of Non-Spherical Black Holes in 5D Einstein Gravity via the Riemann-Hilbert Problem
Jun-ichi Sakamoto, Shinya Tomizawa
https://arxiv.org/abs/2510.02093 https://

Description of Non-Spherical Black Holes in 5D Einstein Gravity via the Riemann-Hilbert Problem
We investigate the solution-generating technique based on the Breitenlohner-Maison (BM) linear system, for asymptotically flat, stationary, bi-axisymmetric black hole solutions with various horizon topologies in five-dimensional vacuum Einstein theory. We construct the monodromy matrix associated with the BM linear system, which provides a unified framework for describing three distinct asymptotically flat, vacuum black hole solutions with a single angular momentum in five dimensions, each with…

Ich habe gerade herausgefunden, dass Albert Einstein eine reale Person war.
Bisher dachte ich er wäre nur ein theoretischer Physiker.
#flachwitzfreitag

Topological interactions in vortex-wave collisions in Bose-Einstein condensates
Vebj{\o}rn {\O}vereng, Andrew Baggaley, Luiza Angheluta
https://arxiv.org/abs/2510.01973 https://…

Topological interactions in vortex-wave collisions in Bose-Einstein condensates
We study vortex-vortex and vortex-wave collisions in two-dimensional weakly interacting Bose-Einstein condensates, processes that play a central role in decaying quantum turbulence. Using numerical simulations of the Gross-Pitaevskii equation, we show that during collisions of vortex-antivortex dipoles, the kinetic energy is transferred from incompressible to compressible modes by two distinct mechanisms. Below the critical vortex separation for annihilation, the transfer is mediated by quantum…

Who's on Second

"Dr. Charles Misner, who passed away in 2023 at the age of 91, was a professor of physics at the University of Maryland from 1963 to 2000, and a renowned expert in General Relativity. He was the recipient of the Albert Einstein medal in 2015, and was the co-author of “Gravitation”, one of the best-selling books in the subject of General Relativity, featuring none other than Kip Thorne on the cover."

Charles Misner & Patrick Cooney
Given the pervasiveness and versatility of computers in our world of 2025 it is easy to ignore that 80 years ago they were initially conceived as what we would call today a calculator, specifically created to solve tedious mathematical problems. Of course, users of TikTok, Call of Duty, YouTube, Visual Studio Code, or even readers of this website through some web browser like Firefox are usually (and blissfully) unaware of the gazillion computations per second that it takes to produce everythin…

Willkommen in der Public Domain, Werke von Albert Einstein, Alexander Fleming, Thomas Mann und Yves Tanguy! Und natürlich der Bebop von Charlie Parker!
#publicdomainday

Point particles on the string in a three-dimensional AdS universe
Petr Luke\v{s}, Pavel Krtou\v{s}
https://arxiv.org/abs/2510.02101 https://arxiv.org/pdf/2…

Point particles on the string in a three-dimensional AdS universe
BTZ spacetime is a long-known locally AdS solution to the Einstein equations in 1 timelike and 2 spacelike dimensions. Its static variant is interpreted as a black hole whose mass is related to the period of the angular coordinate. This solution can be parametrically continued into one without horizons but with a conical deficit in the center. Such a solution is interpreted as a spacetime with a massive particle. It has been shown that this particle can be in static equilibrium with a cosmic st…

Knap hoor, Elon heeft het voor elkaar gekregen om een AI om te bouwen tot een persoonlijke propagandamachine.
https://gizmodo.com/grok-says-elon-musk-is-smarter-than-einstein-and-more-fit-than-lebron-james-2000688999

Grok Says Elon Musk Is Smarter Than Einstein and More Fit Than LeBron James
While Musk wants you to trust Grok to organize all of human civilization's knowledge, the bot's fealty to Dear Leader is out of control.

Electrically tunable ultrafast dynamics and interactions of hybrid excitons in a 2D semiconductor bilayer
Edoardo Lopriore, Charalambos Louca, Armando Genco, Irantzu Landa, Daniel Erkensten, Charles J. Sayers, Samuel Brem, Raul Perea-Causin, Kenji Watanabe, Takashi Taniguchi, Christoph Gadermaier, Ermin Malic, Giulio Cerullo, Stefano Dal Conte, Andras Kis
https…

Electrically tunable ultrafast dynamics and interactions of hybrid excitons in a 2D semiconductor bilayer
Extended efforts have been devoted to the study of strongly-interacting excitons and their dynamics, towards macroscopic quantum states of matter such as Bose-Einstein condensates of excitons and polaritons. Momentum-direct layer-hybridized excitons in transition metal dichalcogenides have attracted considerable attention due to their high oscillator strength and dipolar nature. However, the tunability of their interactions and dynamics remains unexplored. Here, we achieve an unprecedented cont…

from my link log —
Einstein: NewtonOS running on other operating systems.
https://github.com/pguyot/Einstein
saved 2025-12-08 https://dotat.at/:/S89W…

GitHub - pguyot/Einstein: NewtonOS running on other operating systems
NewtonOS running on other operating systems. Contribute to pguyot/Einstein development by creating an account on GitHub.

Six-dimensional cosmological models with conformal extensions
Daniel Muller, Sergey G. Rubin, Ilya L. Shapiro, Alexey Toporensky
https://arxiv.org/abs/2510.01534 https://…

Six-dimensional cosmological models with conformal extensions
We consider the background cosmological solutions in the $6D$ (six-dimensional) model with one time and five space coordinates. The theory of our interest has the action composed by the Einstein term, cosmological constant, and two conformal terms constructed from the third powers of the Weyl tensor. It is shown how the highest derivative terms in the equations of motion can be isolated that opens the way for their numerical integration. There are flat anisotropic solutions which make one of th…

Auch das noch
https://nrw.social/@scinexx/115421903119616149

Anisotropic and non-additive interactions of a Rydberg impurity in a quantum bath
Aileen A. T. Durst, Seth T. Rittenhouse, H. R. Sadeghpour, Matthew T. Eiles
https://arxiv.org/abs/2510.01497

Anisotropic and non-additive interactions of a Rydberg impurity in a quantum bath
We present a framework for treating anisotropic and non-additive impurity-bath interactions - features that are ubiquitous in realistic quantum impurity problems, but are often neglected in conventional approaches relying on additive, spherically symmetric pseudopotentials. To illustrate this, we focus on a Rydberg atom immersed in a Bose-Einstein condensate, where the internal-state degeneracy of the Rydberg impurity gives rise to configuration-dependent non-additive potentials. With increasin…

Einstein's theory comes wrapped up with a bow: Astronomers spot star 'wobbling' around black hole
https://phys.org/news/2025-12-einstein-theory-astronomers-star-black.html

so there's skeleton decorations down State Street but SOMETHING WENT VERY WRONG WITH THE LAST ONE AND I COULD NOT STOP LAUGHING

#NowReading

Poincar\'e-Einstein 4-manifolds with conformally K\"ahler geometry
Mingyang Li, Hongyi Liu
https://arxiv.org/abs/2510.04928 https://arxiv.org/pdf/…

Poincaré-Einstein 4-manifolds with conformally Kähler geometry
We study 4-dimensional Poincaré-Einstein manifolds whose conformal class contains a Kähler metric. Such Einstein metrics are non-Kähler and admit a Killing field extending to the conformal infinity, and the Einstein equation reduces to a Toda-type equation. When the Killing field integrates to an $\mathbb{S}^1$-action, we formulate a Dirichlet boundary value problem and establish existence and uniqueness theory. This construction provides a non-perturbative realization of infinite-dimensiona…

RE: https://openbiblio.social/@awinkler/115802117539511437

RE: https://openbiblio.social/@awinkler/115802117539511437

New Evidence for Extragalactic Einstein Probe Transients associated with Long Gamma-ray Bursts
Qin-Mei Li, Qi-Bin Sun, Sheng-Bang Qian, Fu-Xing Li
https://arxiv.org/abs/2510.10267

New Evidence for Extragalactic Einstein Probe Transients associated with Long Gamma-ray Bursts
The origin of extragalactic fast X-ray transients (EFXTs) remains a fundamental open question in high-energy astrophysics. The Einstein Probe (EP) mission provides a transformative opportunity to investigate their nature. While mounting observations of EP-discovered EFXTs (EP-EFXTs) suggest a possible connection to long gamma-ray bursts (lGRBs), an in-depth comparative analysis between them remains lacking. Here, we present a comparative analysis of their cosmic formation histories, revealing t…

Semi-Global Existence and Trapped Surface Formation for the Einstein-Vlasov System
Nikolaos Athanasiou, Puskar Mondal, Shing-Tung Yau
https://arxiv.org/abs/2510.12429 https://…

Semi-Global Existence and Trapped Surface Formation for the Einstein-Vlasov System
We prove a large-data semi-global existence theorem and the dynamical formation of trapped surfaces for the Einstein-massless Vlasov system in 3+1 dimensions, without any symmetry assumptions. The analysis critically hinges on a finely calibrated hierarchy of estimates for the Weyl curvature, Ricci coefficients, and velocity moments of the distribution function, designed to capture the delicate interaction between the geometric and kinetic structures of the coupled system. The presence of the V…

Possible Bose-Einstein condensation of magnons in a S = 5/2 honeycomb lattice
J. Khatua, S. M. Kumawat, G. Senthil Murugan, C. -L. Huang, Heung-Sik Kim, K. Sritharan, R. Sankar, Kwang-Yong Choi
https://arxiv.org/abs/2510.12682

Possible Bose-Einstein condensation of magnons in a S = 5/2 honeycomb lattice
Quantum magnets offer a unique platform for exploring exotic quantum phases and quantum phase transitions through external magnetic fields. A prominent example is the field-induced Bose--Einstein condensation (BEC) of magnons near the saturation field. While this behavior has been observed in low-spin systems, its realization in high-spin, quasi-two-dimensional magnets -- where multiple on-site excitations are possible -- remains exceptionally rare. Here, we report thermodynamic and density fun…

On Geometric Structures in the Einstein Universe for $\mathrm{SO}_0(p,p 1)$-Hitchin Representations
Colin Davalo, Parker Evans
https://arxiv.org/abs/2510.12779 https://

On Geometric Structures in the Einstein Universe for $\mathrm{SO}_0(p,p+1)$-Hitchin Representations
Let $S$ be a closed surface of genus $g \geq 2$. We determine the topology of the fibers of the domain of discontinuity in $\mathrm{Ein}^{p-1,p}$ defined by Guichard-Wienhard and Kapovich-Leeb-Porti for $\mathrm{SO}_0(p,p+1)$-Hitchin representations for $p \geq 3$.

Einstein and Debye temperatures, electron-phonon coupling constant and a probable mechanism for ambient-pressure room-temperature superconductivity in intercalated graphite
E. F. Talantsev
https://arxiv.org/abs/2511.07460 https://arxiv.org/pdf/2511.07460 https://arxiv.org/html/2511.07460
arXiv:2511.07460v1 Announce Type: new
Abstract: Recently, Ksenofontov et al (arXiv:2510.03256) observed ambient pressure room-temperature superconductivity in graphite intercalated with lithium-based alloys with transition temperature (according to magnetization measurements) $T_c=330$ $K$. Here, I analyzed the reported temperature dependent resistivity data $\rho(T)$ in these graphite-intercalated samples and found that $\rho(T)$ is well described by the model of two series resistors, where each resistor is described as either an Einstein conductor or a Bloch-Gr\"uneisen conductor. Deduced Einstein and Debye temperatures are $\Theta_{E,1} \approx 250$ $K$ and $\Theta_{E,2} \approx 1,600$ $K$, and $\Theta_{D,1} \approx 300$ $K$ and $\Theta_{D,2} \approx 2,200$ $K$, respectively. Following the McMillan formalism, from the deduced $\Theta_{E,2}$ and $\Theta_{D,2}$, the electron-phonon coupling constant $\lambda_{e-ph} = 2.2 - 2.6$ was obtained. This value of $\lambda_{e-ph}$ is approximately equal to the value of $\lambda_{e-ph}$ in highly compressed superconducting hydrides. Based on this, I can propose that the observed room-temperature superconductivity in intercalated graphite is localized in nanoscale Sr-Ca-Li metallic flakes/particles, which adopt the phonon spectrum from the surrounding bulk graphite matrix, and as a result, conventional electron-phonon superconductivity arises in these nano-flakes/particles at room temperature. Experimental data reported by Ksenofontov et al (arXiv:2510.03256) on trapped magnetic flux decay in intercalated graphite samples supports the proposition.
toXiv_bot_toot

Non-conformally Einstein instantons in Conformal Gravity with and without nonlinear matter fields
Crist\'obal Corral, Borja Diez, Eleftherios Papantonopoulos
https://arxiv.org/abs/2510.11854

Non-conformally Einstein instantons in Conformal Gravity with and without nonlinear matter fields
In this work, we study non-conformally Einstein gravitational instantons in four-dimensional Conformal Gravity, both in vacuum and in the presence of nonlinear conformal matter. First, the one-parameter extension of the Kerr-NUT-AdS metric is analyzed. We obtain their conserved charges by using the Noether-Wald formalism. It turns out that they receive corrections from the linear modes present in Conformal Gravity, which are properly identified. Then, we perform the analytic continuation into t…

Dynamic micromagnetism a la Ericksen-Leslie, allowing the Einstein-de Haas and Barnett effects
Amit Acharya, Siladitya Pal
https://arxiv.org/abs/2510.04393 https://

Dynamic micromagnetism a la Ericksen-Leslie, allowing the Einstein-de Haas and Barnett effects
A model of dissipative micromagnetics coupled to elasticity is developed, following the procedures of the Ericksen-Leslie theory of nematic liquid crystals allowing for angular momentum due to magnetization. An outcome is the Landau-Lifshitz-Gilbert theory coupled to material spin. A further power-less augmentation to the angular momentum of the theory with classical kinetic energy density is also considered, which allows for plausible approaches to model the Einstein-de Haas and Barnett effect…

Comment on "Comment on Galina Weinstein's article entitled 'Convergences and Divergences: Einstein Poincar\'e and Special Relativity' "
Galina Weinstein
https://arxiv.org/abs/2510.03793

Comment on "Comment on Galina Weinstein's article entitled 'Convergences and Divergences: Einstein Poincaré and Special Relativity' "
This paper provides a systematic response to the criticisms raised by Jean-Marc Ginoux in response to my review of his book on the history of relativity. Whereas my review was written in a strictly academic manner, Ginoux's commentary intermingles mathematical objections with ad hominem insinuations about both Einstein and me. The purpose of this reply is twofold: first, to clarify the historiographical and conceptual issues at stake in the interpretation of Einstein's 1905 paper and Poincaré'…

Looking to the past for inspiration? 📚 Iconic figures like Winston Churchill and Albert Einstein inspire resilience and insight. They remind us that challenges are just stepping stones to greatness. Which historical figure inspires you to think bigger and dream boldly? Let's discuss! #Inspiration #HistoryLovers

RE: https://mastodon.social/@gutenberg_org/115514343451302035
For those curious if Einstein would've gone to Epstein island.

Einstein-Maxwell Equations on Mass-Centered GCM Hypersurfaces
Allen Juntao Fang, Elena Giorgi, Jingbo Wan
https://arxiv.org/abs/2510.10814 https://arxiv.or…

Einstein-Maxwell Equations on Mass-Centered GCM Hypersurfaces
The resolution of the nonlinear stability of black holes as solutions to the Einstein equations relies crucially on imposing the right geometric gauge conditions. In the vacuum case, the use of Generally Covariant Modulated (GCM) spheres and hypersurfaces has been successful in the proof of stability for slowly rotating Kerr spacetime. For the charged setting, our companion paper introduced an alternative mass-centered GCM framework, adapted to the additional difficulties of the Einstein-Maxwel…

X-mas comes early this year: the ICFP 2025 talks are now on YouTube.
You can catch my talk on "Domain-specific tensor languages" below. We explore implementing tensor calculus in #Haskell, supporting both Einstein notation and Penrose diagrams to model things like General Relativity and black holes. 🕳️🚀
My talk:

Non-closed scalar charge in 4-dimensional Einstein-scalar-Gauss-Bonnet black hole thermodynamics
Romina Ballesteros, Marcela C\'ardenas, Eric Lescano
https://arxiv.org/abs/2510.08686

Non-closed scalar charge in 4-dimensional Einstein-scalar-Gauss-Bonnet black hole thermodynamics
We develop a covariant differential-form framework to define scalar charges for stationary, asymptotically flat black holes in $4$--dimensional Einstein-scalar-Gauss-Bonnet gravity with a general scalar coupling function. Contracting the scalar field equation of motion with the horizon generator $k$ yields a non-closed-form scalar charge, revealing a bulk contribution encoded in a $3$--form, which measures the obstruction to its closedness. In the presence of shift-symmetry, this obstruction va…

From Lasers to Photon Bose--Einstein Condensates: A Unified Description via an Open-Dissipative Bose--Einstein Distribution
Joshua Krau{\ss}, Enrico Stein, Axel Pelster
https://arxiv.org/abs/2510.05917

From Lasers to Photon Bose--Einstein Condensates: A Unified Description via an Open-Dissipative Bose--Einstein Distribution
Photon condensation was first experimentally realized in 2010 within a dye-filled microcavity at room temperature. Since then, interest in the field has increased significantly, as a photon Bose-Einstein condensate (BEC) represents a prototypical driven-dissipative system. Here, we investigate how its inherent open nature influences the condensation process both quantitatively and qualitatively. To this end, we consider a mean-field model, which can be derived microscopically from a Lindblad ma…

Fast radio bursts shed light on direct gravity test on cosmological scales
Shuren Zhou, Pengjie Zhang
https://arxiv.org/abs/2510.11022 https://arxiv.org/pd…

Fast radio bursts shed light on direct gravity test on cosmological scales
A key measure of gravity is the relation between the Weyl potential $Ψ+Φ$ and the matter overdensity $δ_m$, capsulized as an effective gravitational constant $G_{\rm light}$ for light motion. Its value, together with the possible spatial and temporal variation, is essential in probing physics beyond Einstein gravity. However, the lack of an unbiased proxy of $δ_m$ prohibits direct measurement of $G_{\rm light}$. We point out that the equivalence principle ensures the dispersion measure (DM)…

New AF Einstein--Maxwell instantons
Bernardo Araneda, Maciej Dunajski
https://arxiv.org/abs/2510.06458 https://arxiv.org/pdf/2510.06458

New AF Einstein--Maxwell instantons
We explicitly construct a three--parameter family of asymptotically flat Einstein--Maxwell instantons. These solutions are toric, regular, and free of conical and orbifold singularities on the manifold $M=\CP^2\setminus S^1$. They are counterexamples to the Euclidean Einstein--Maxwell Black Hole Uniqueness Conjecture. In the case of vanishing charge these instantons reduce to the Chen--Teo Ricci flat instantons.

Replaced article(s) found for quant-ph. https://arxiv.org/list/quant-ph/new
[3/3]:
- Recovering Einstein's equation from local correlations with quantum reference frames
Eduardo O. Dias

Collective excitation of Bose-Einstein condensate of Bose atoms with P\"oschl-Teller interaction
Avra Banerjee, Arnab Bhowmik, Dwipesh Majumder
https://arxiv.org/abs/2510.13383

Identification and optimal control strategies for the transversal splitting of ultra--cold Bose gases
Nikolaus W\"urkner, Yevhenii Kuriatnikov, Karthikeyan Kumaran, Marupaka Venkat Ramana, J\"org Schmiedmayer, Andreas Kugi, Maximilian Pr\"ufer, Andreas Deutschmann-Olek
https://arxiv.org/abs/2510.07113

Identification and optimal control strategies for the transversal splitting of ultra--cold Bose gases
Splitting a Bose--Einstein condensate (BEC) is a key operation in fundamental physics experiments and emerging quantum technologies, where precise preparation of well--defined initial states requires fast yet coherent control of the condensate's nonlinear dynamics. This work formulates the BEC splitting process as an optimal feedforward control problem based on a physically interpretable, reduced--order model identified from limited experimental data. We introduce a systematic calibration strat…

Enhancing the mass resolving power of FRIB's proposed high-voltage MR-ToF mass separator and spectrometer: addressing non-ideal conditions
Christian Michael Ireland, Franziska Maria Maier, Einstein Dhayal, Erich Leistenschneider, Ryan Ringle, Austin Sjaarda
https://arxiv.org/abs/2510.11741

Enhancing the mass resolving power of FRIB's proposed high-voltage MR-ToF mass separator and spectrometer: addressing non-ideal conditions
Multi-reflection time-of-flight mass separators and spectrometers (MR-ToF MSs) are indispensable tools at radioactive ion beam (RIB) facilities. These electrostatic ion beam traps act as highly selective mass separators and high-precision mass spectrometers for rare and exotic nuclei. When well-tuned and designed to minimize higher-order flight-time aberrations, state-of-the-art MR-ToF MSs approach, and slightly exceed, mass resolving powers of \( m / Δm = 10^6 \). Achieving \( m / Δm > 3 \cd…

Stability of vortex lattices in rotating flows
Juli\'an Amette Estrada, Alexandros Alexakis, Marc E. Brachet, Pablo D. Mininni
https://arxiv.org/abs/2510.06374 https://

Stability of vortex lattices in rotating flows
Vortex lattices -- highly ordered arrays of vortices -- are known to arise in quantum systems such as type II superconductors and Bose-Einstein condensates. More recently, similar arrangements have been reported in classical rotating fluids. However, the mechanisms governing their formation, stability, and eventual breakdown remain poorly understood. We explore the dynamical stability of vortex lattices in three-dimensional rotating flows. To that end we construct controlled initial conditions …

A century of the Bose-Einstein condensation concept and half a century of the JINR experiments for observation of condensate in the superfluid 4He (He II)
Valentin Zagrebnov (I2M)
https://arxiv.org/abs/2510.03378

A century of the Bose-Einstein condensation concept and half a century of the JINR experiments for observation of condensate in the superfluid 4He (He II)
This short review is devoted to celebration of two major events in quantum physics. The first one is the birth of the concept of Bose-Einstein condensation (1925) and the second is the experimental proof that it does exist and appears in the liquid 4He simultaneously with superfluidity below the $λ$-point (1975). The both of these events are tightly related to the Bogoliubov theory of superfluidity (1947). The existence of condensate in the system of interacting bosons is the key ansatz of thi…

Replaced article(s) found for cond-mat.stat-mech. https://arxiv.org/list/cond-mat.stat-mech/new
[1/1]:
- Derivation of Bose-Einstein statistics from the uncertainty principle
Paul Tangney

Revised comment on the paper titled "The Origin of Quantum Mechanical Statistics: Insights from Research on Human Language
Miko{\l}aj Sienicki, Krzysztof Sienicki
https://arxiv.org/abs/2512.07881 https://arxiv.org/pdf/2512.07881 https://arxiv.org/html/2512.07881
arXiv:2512.07881v1 Announce Type: new
Abstract: This short note comments on \citet{Aerts2024Origin}, which proposes that ranked word frequencies in texts should be read through the lens of Bose--Einstein (BE) statistics and even used to illuminate the origin of quantum statistics in physics. The core message here is modest: the paper offers an interesting analogy and an eye-catching fit, but several key steps mix physical claims with definitions and curve-fitting choices. We highlight three such points: (i) a normalization issue that is presented as "bosonic enhancement", (ii) an identification of rank with energy that makes the BE fit only weakly diagnostic of an underlying mechanism, and (iii) a baseline comparison that is too weak to support an ontological conclusion. We also briefly flag a few additional concerns (interpretation drift, parameter semantics, and reproducibility).
toXiv_bot_toot

Geometric filtering effect in expanding Bose-Einstein condensate shells
Andrea Tononi, Maciej Lewenstein, Luis Santos
https://arxiv.org/abs/2510.12309 https://

Geometric filtering effect in expanding Bose-Einstein condensate shells
A shell-shaped Bose-Einstein condensate released from its confinement expands radially both outwards and inwards, displaying a self-interference pattern characterized by a density peak surrounded by a halo. Here we analyze how an external imprinting or the thermal fluctuations of the condensate phase influence this expansion. In both cases, we find that the curved geometry filters the imploding finite angular-momentum modes via a radial centrifugal potential, so that only the condensate state c…

🇺🇦 #NowPlaying on BBCRadio3's #EarlierWithJoolsHolland
Philip Glass, Philip Glass Ensemble & Michael Riesman:
🎵 Einstein on the beach: Act 1; Train 1
#PhilipGlass #PhilipGlassEnsemble #MichaelRiesman
https://open.spotify.com/track/2ga5HWiAHUon3G6hW03zZJ

Newly scalarization of the Einstein-Euler-Heisenberg black hole
Lina Zhang, De-Cheng Zou, Yun Soo Myung
https://arxiv.org/abs/2510.07954 https://arxiv.org/…

Newly scalarization of the Einstein-Euler-Heisenberg black hole
Th spontaneous scalarization of the Einstein-Euler-Heisenberg (EEH) black hole is performed in the EEH-scalar theory by introducing an exponential scalar coupling (with $α$ coupling constant) to the Maxwell term.Here, the EEH black hole as a blad black hole is described by mass $M$ and magnetic charge $q$ with an action parameter $μ$. A choice of $μ=0.3$ gurantees a single horizon with unrestricted magnetic charge $q$. The onset scalarization of this black hole appears for a positive couplin…

Crosslisted article(s) found for math.DG. https://arxiv.org/list/math.DG/new
[1/1]:
- Semi-Global Existence and Trapped Surface Formation for the Einstein-Vlasov System
Nikolaos Athanasiou, Puskar Mondal, Shing-Tung Yau

Stable High-Order Vortices in Spin-Orbit-Coupled Spin-1 Bose-Einstein Condensates
Xin-Feng Zhang, Huan-Bo Luo, Josep Batle, Bin Liu, Yongyao Li
https://arxiv.org/abs/2510.09832 …

Stable High-Order Vortices in Spin-Orbit-Coupled Spin-1 Bose-Einstein Condensates
The present contribution explores phase transitions that occur in the ground state (GS) of spin-1 Bose-Einstein condensates (BECs) with spin-orbit coupling (SOC) under the action of gradient magnetic fields. By solving the corresponding linearized system in an exact fashion, we identify the conditions under which the GS phase transitions occur, thus transforming excited states into GS. The study of the full nonlinear system, including both density-density and spin-spin interactions, is …

Is Dark Energy Changing? Probing the Universe's Expansion with present and future astronomical probes
Mehdi Rezaei, Supriya Pan, Weiqiang Yang, David F. Mota
https://arxiv.org/abs/2510.09766

Is Dark Energy Changing? Probing the Universe's Expansion with present and future astronomical probes
This study explores the possibility of a time-varying dark energy (DE) equation of state (EoS) deviating from -1. We employ a comprehensive dataset of usual astronomical probes (Type Ia supernovae, baryon acoustic oscillations, Big Bang nucleosynthesis, Hubble data, and Planck 2018 CMB) alongside future mock gravitational wave (GW) distance measurements from the Einstein Telescope. We utilize the Pad'e approximation, a versatile framework encompassing well-known DE models like constant EoS, Che…

Scalar-tensor theories in the Lyra geometry: Invariance under local transformations of length units and the Jordan-Einstein frame conundrum
E. C. Valad\~ao, Felipe Sobrero, Santiago Esteban Perez Bergliaffa
https://arxiv.org/abs/2510.08433

Scalar-tensor theories in the Lyra geometry: Invariance under local transformations of length units and the Jordan-Einstein frame conundrum
The Lyra geometry provides an interesting approach to develop purely geometrical scalar-tensor theories due to the natural presence of the Lyra scale function. This paper explores further the scale function source term to construct a theory on Lyra manifolds which contains proper generalizations of both Brans-Dicke gravity and the Einstein-Gauss-Bonnet scalar-tensor theory. It is shown that the symmetry group of gravitational theories on the Lyra geometry comprises not only coordinate transform…

Replaced article(s) found for physics.atom-ph. https://arxiv.org/list/physics.atom-ph/new
[1/1]:
- Probing the spatial distribution of k-vectors in situ with Bose-Einstein condensates
Gaudout, Si-Ahmed, Debavelaere, Door, Clad\'e, Guellati-Khelifa

Dyonic RN-like and Taub-NUT-like black holes in Einstein-bumblebee gravity
Shoulong Li, Liang Liang, Liang Ma
https://arxiv.org/abs/2510.04405 https://arxi…

Dyonic RN-like and Taub-NUT-like black holes in Einstein-bumblebee gravity
Einstein-bumblebee gravity is one of the simplest vector-tensor theories that realizes spontaneous Lorentz symmetry breaking. In this work, we first construct an exact dyonic Reissner-Nordström-like black hole solution in four dimensions, carrying both electric and magnetic charges and admitting general topological horizons. We then study its thermodynamic properties, and employ the Wald formalism to compute the conserved mass and entropy, thereby establishing the first law of black hole therm…

de Sitter versus Anti de Sitter flows and the (super)gravity landscape: Part II
Elias Kiritsis, Sergio Morales-Tejera, Christopher Rosen
https://arxiv.org/abs/2510.12373 https:/…

de Sitter versus Anti de Sitter flows and the (super)gravity landscape: Part II
Generic solutions are studied in Einstein-scalar gravity in an ansatz that can interpolate between de Sitter and Anti-de Sitter regimes. The scalar potential is arbitrary. All solutions are determined by their end-points in the scalar field space. All such end-points are classified. This provides a complete classification and characterization of the full space of regular solutions. It is shown that there are no regular (Centaur) solutions that interpolate between an AdS boundary and a dS interi…

Analytic and accurate approximate metrics for black holes with arbitrary rotation in beyond-Einstein gravity using spectral methods
Kelvin Ka-Ho Lam, Adrian Ka-Wai Chung, Nicol\'as Yunes
https://arxiv.org/abs/2510.05208

Analytic and accurate approximate metrics for black holes with arbitrary rotation in beyond-Einstein gravity using spectral methods
A key obstacle for theory-specific tests of general relativity is the lack of accurate black-hole solutions in beyond-Einstein theories, especially for moderate to high spins. We address this by developing a general framework--based on spectral and pseudospectral methods--to obtain analytic, closed-form spacetimes representing stationary, axisymmetric black holes in effective-field-theory extensions of general relativity to leading order in the coupling constants. The approach models the spacet…

Faraday patterns, spin textures, spin-spin correlations and competing instabilities in a driven spin-1 antiferromagnetic Bose-Einstein condensate
Vaishakh Kargudri, Sandra M. Jose, Rejish Nath
https://arxiv.org/abs/2510.08087

Faraday patterns, spin textures, spin-spin correlations and competing instabilities in a driven spin-1 antiferromagnetic Bose-Einstein condensate
We study the formation of transient Faraday patterns and spin textures in driven quasi-one-dimensional and quasi-two-dimensional spin-1 Bose-Einstein condensates under the periodic modulation of $s$-wave scattering lengths $a_0$ and $a_2$, starting from the anti-ferromagnetic phase. This phase is characterized by a Bogoliubov spectrum consisting of three modes: one mode is gapped, while the other two are gapless. When $a_0$ is modulated and half of the modulation frequency lies below the gapped…

The dark sector of the Universe as a scalar field in Horndeski Gravity
M. S. Oliveira, F. A. Brito, J. A. V. Campos
https://arxiv.org/abs/2510.08459 https://

The dark sector of the Universe as a scalar field in Horndeski Gravity
In the present work, we study a subclass of Horndeski gravity characterized by a non-minimal derivative coupling between a scalar field and the Einstein tensor, as a possible alternative to alleviate the observational tension associated with estimates of the Hubble constant $H_{0}$. Two scenarios within a flat FRW spacetime were considered. In the first case, the scalar field mimics cold dark matter, whereas in the second case, it acts as dark energy. We derive the dynamical equations and perfo…

On thermal holographic RG flows
Elena C\'aceres, Hare Krishna
https://arxiv.org/abs/2510.09955 https://arxiv.org/pdf/2510.09955

On thermal holographic RG flows
Holographic Renormalization Group (RG) flows, described by Einstein gravity coupled to matter fields, have been thoroughly explored in the context of vacuum states. In this work, we shift the focus to thermal states. Using the Hamilton-Jacobi formalism for the coupled system, we derive the Ward identity associated with broken dilatation symmetry in thermal correlators and obtain the modified Callan-Symanzik equation for the dual thermal CFT. We then employ the Hamiltonian approach to analyze th…

Crosslisted article(s) found for physics.atom-ph. https://arxiv.org/list/physics.atom-ph/new
[1/1]:
- Macroscopic Self-Trapping and Dynamical Phase Transition in Momentum Space Bose-Einstein Condensates
Schimelfenig, Serrano, Halverson, Mukhopadhyay, Guan, Engels

Replaced article(s) found for cond-mat.quant-gas. https://arxiv.org/list/cond-mat.quant-gas/new
[1/1]:
- Observation of the Einstein-de Haas Effect in a Bose-Einstein condensate
Matsui, Miyazawa, Goto, Nakano, Kawaguchi, Ueda, Kozuma

Wormholes in Einstein-Dirac-Maxwell theory with identical spacetime asymptotics
Vladimir Dzhunushaliev, Vladimir Folomeev, Nurzada Beissen, Adilet Nurmukhamedov
https://arxiv.org/abs/2510.03656

Wormholes in Einstein-Dirac-Maxwell theory with identical spacetime asymptotics
Within general relativity, we study spherically symmetric configurations with wormhole topology consisting of spinor fields and a Maxwell electric field. For such a system, we construct complete families of regular asymmetric solutions describing wormholes connecting two identical Minkowski spacetimes. The physical properties of such systems are completely determined by the values of three input quantities: the throat parameter, the spinor frequency, and the coupling constant. Depending on the …

Replaced article(s) found for astro-ph.CO. https://arxiv.org/list/astro-ph.CO/new
[2/2]:
- ACT inflation and its influence on reheating era in Einstein-Gauss-Bonnet gravity
Sergei D. Odintsov, Tanmoy Paul

Heterotic Footprints in Classical Gravity: PM dynamics from On-Shell soft amplitudes at one loop
Arpan Bhattacharyya, Saptaswa Ghosh, Ankit Mishra, Sounak Pal
https://arxiv.org/abs/2510.07390

Heterotic Footprints in Classical Gravity: PM dynamics from On-Shell soft amplitudes at one loop
We study classical scattering of charged black holes in Einstein-Maxwell-Dilaton (EMD) theory. Working in the classical (Post-Minkowskian) regime, we extract the conservative two-body potential by expanding the one loop amplitudes in the soft regime. We show explicitly that, as in GR, the relevant soft amplitudes are infrared (IR) finite once the long-range interactions are consistently treated via Lippmann-Schwinger equation and the associated IR subtraction. The scattering angle is then obtai…

Using Gauge Covariant Lie Derivatives in Einstein-Cartan and Metric Teleparallel Theories of Gravity
R. J. van den Hoogen, H. Forance, L. Taylor, M. Lawton
https://arxiv.org/abs/2510.03082

Using Gauge Covariant Lie Derivatives in Einstein-Cartan and Metric Teleparallel Theories of Gravity
A procedure to determine the initial ansatz for the co-frame and spin connection characterizing a Riemann-Cartan geometry respecting a given group of continuous symmetries is illustrated. Given a particular group of symmetries and assuming an orthonormal gauge we can determine the co-frame and corresponding spin connection having this symmetry group by employing an gauge covariant Lie derivative. This gauge covariant Lie derivative when applied to the metric and co-frame determines the values o…

Replaced article(s) found for physics.atom-ph. https://arxiv.org/list/physics.atom-ph/new
[1/1]:
- Perturbation-assisted Observation of the Lowest Vibrational Level of the $\mathrm{b}^{3}\Pi_{0}$ ...
Yang, Nie, Yu, Liu, Avalos, He, Klos, Kotochigova, Dieckmann
https://arxiv.org/abs/2510.17166 https://mastoxiv.page/@arXiv_physicsatomph_bot/115411364513995859
- Direct Measurement of the $5s5p\,{}^1P_1 \to 5s4d\,{}^1D_2$ Decay Rate in Strontium
Naohiro Okamoto, Takatoshi Aoki, Yoshio Torii
https://arxiv.org/abs/2510.22184 https://mastoxiv.page/@arXiv_physicsatomph_bot/115450966319591523
- Turbulence and far-from-equilibrium equation of state of Bogoliubov waves in Bose-Einstein Conden...
Ying Zhu, Giorgio Krstulovic, Sergey Nazarenko
https://arxiv.org/abs/2408.15163 https://mastoxiv.page/@arXiv_condmatquantgas_bot/113038670682163852
- Observation of quantum free fall and the consistency with the equivalence principle
Or Dobkowski, et al.
https://arxiv.org/abs/2502.14535 https://mastoxiv.page/@arXiv_quantph_bot/114040790353608831
- Microwave-field quantum metrology with inherent robustness against detection losses enabled by Ry...
Kurzyna, Niewelt, Mazelanik, Wasilewski, Demkowicz-Dobrza\'nski, Parniak
https://arxiv.org/abs/2505.01506 https://mastoxiv.page/@arXiv_quantph_bot/114459737137154531
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The Anholonomic Frame and Connection Deformation Method for constructing off-diagonal solutions in (modified) Einstein gravity and nonassociative geometric flows and Finsler-Lagrange-Hamilton theories
Lauren\c{t}iu Bubuianu, Julia O. Seti, Douglas Singleton, Sergiu I. Vacaru, El\c{s}en Veli Veliev
https://arxiv.org/abs/2510.02321

The Anholonomic Frame and Connection Deformation Method for constructing off-diagonal solutions in (modified) Einstein gravity and nonassociative geometric flows and Finsler-Lagrange-Hamilton theories
This article is a status report on the Anholonomic Frame and Connection Deformation Method, AFCDM, for constructing generic off-diagonal exact and parametric solutions in general relativity, GR, relativistic geometric flows, and modified gravity theories, MGTs. Such models can be generalized to nonassociative and noncommutative star products on phase spaces and modelled equivalently as nonassociative Finsler-Lagrange-Hamilton geometries. Our approach involves a nonholonomic geometric reformulat…

Scalar Quasinormal modes in Reissner--Nordstr\"om black holes: implications for Weak Gravity Conjecture
Giorgio Di Russo, Anna Tokareva
https://arxiv.org/abs/2510.06813 htt…

Scalar Quasinormal modes in Reissner--Nordström black holes: implications for Weak Gravity Conjecture
Microscopic charged black holes can provide possibilities to test the consistency of the effective field theory (EFT) corrections to Einstein-Maxwell theory. A particularly interesting result is fixing the sign of a certain combination of EFT couplings from the requirement that all charged black holes should be able to evaporate (Weak Gravity Conjecture). In our work, we analysed the EFT corrections to a set of zero-damping quasinormal modes (QNMs) of the scalar wave probe in a nearly extremal …

On the Invariant and Geometric Structure of the Holomorphic Unified Field Theory
J. W. Moffat, E. J. Thompson
https://arxiv.org/abs/2510.06282 https://arxi…

On the Invariant and Geometric Structure of the Holomorphic Unified Field Theory
We present the invariant structure of a Holomorphic Unified Field Theory in which gravity and gauge interactions arise from a single geometric framework. The theory is formulated on a product principal bundle, with one connection, and curvature equipped with a Hermitian field on a complexification of spacetime. From a single Diff(M) $\times$ G-invariant action, variation yields the Einstein and Yang-Mills equations together with their paired Bianchi identities. A compatibility condition is impl…

Phase structure of a holographic topological superconductor beyond the probe limit
Hoang Van Quyet
https://arxiv.org/abs/2510.05941 https://arxiv.org/pdf/2…

Phase structure of a holographic topological superconductor beyond the probe limit
We investigate tricritical phase transitions in a holographic model of topological superconductivity using Einstein-Maxwell gravity coupled with a charged scalar field in Anti-de Sitter spacetime. By incorporating both gravitational backreaction and quartic self-interaction $V(ϕ) = λϕ^4$, we demonstrate that the system exhibits both second-order and first-order phase transitions separated by a tricritical point at $(q_{\mathrm{tri}},T_{\mathrm{tri}})=(2.00\pm0.02,0.1521\pm0.0003)$ in the $(q…

Crosslisted article(s) found for physics.atom-ph. https://arxiv.org/list/physics.atom-ph/new
[1/1]:
- Mechanical Stability of 2D Ti2COx MXenes Under Compression Using Reactive Molecular Dynamics
Hossein Darban
https://arxiv.org/abs/2512.05166 https://mastoxiv.page/@arXiv_condmatmtrlsci_bot/115683094055082376
- Squeezing Classical Antiferromagnets into Quantum Spin Liquids via Global Cavity Fluctuations
Mann, Oehlgrien, Jaworowski, Calaj\'o, Marino, Choi, Chang
https://arxiv.org/abs/2512.05630 https://mastoxiv.page/@arXiv_quantph_bot/115683366016729915
- Quenching dynamics of vortex in spin-orbit coupled Bose-Einstein condensates
Juan Wang, Zhenze Fan, Yan Li
https://arxiv.org/abs/2512.05691 https://mastoxiv.page/@arXiv_condmatquantgas_bot/115682862702776327
- Computer simulations of the Stark effect in the helium-beta complex of krypton in ICF conditions
G. P\'erez-Callejo, E. Stambulchik, R. Florido, M. A. Gigosos
https://arxiv.org/abs/2512.05903 https://mastoxiv.page/@arXiv_physicsplasmph_bot/115683224476329386
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Quantum many-body analysis of a spin-2 bosons with two-body inelastic decay
Takeshi Takahashi, Hiroki Saito
https://arxiv.org/abs/2510.10050 https://arxiv.…

Quantum many-body analysis of a spin-2 bosons with two-body inelastic decay
Bose-Einstein condensates (BECs) of $^{87}\textrm{Rb}$ atoms with a hyperfine spin of 2 are open quantum systems, where the atoms are lost through two-body inelastic collisions. In this dissipation process, a collision channel with total spin of 4 is forbidden by angular momentum conservation, which results in magnetization of the atoms remaining in the condensate. Here, we investigate the quantum many-body properties of spin-2 bosons that undergo two-body atomic loss. We show that the system f…

Relevant Deformations, Brane Brick Models and Triality
Mario Carcamo, Sebastian Franco, Dongwook Ghim, Georgios P. Goulas, Rak-Kyeong Seong
https://arxiv.org/abs/2510.05517 http…

Relevant Deformations, Brane Brick Models and Triality
We extend the study of relevant deformations connecting 2d (0,2) gauge theories on D1-branes probing toric Calabi-Yau 4-folds beyond pure mass deformations. The underlying geometry provides powerful insights when field-theoretic tools are still lacking. We observe that the volume of the Sasaki-Einstein base of the Calabi-Yau 4-fold grows towards the IR, signaling the relevance of deformations. We exploit the map between gauge theory fields and GLSM fields to compute scaling dimensions directly …

Impact of facility timing and coordination for next-generation gravitational-wave detectors
Ssohrab Borhanian, Arianna Renzini, Philippa S. Cole, Costantino Pacilio, Michele Mancarella, Davide Gerosa
https://arxiv.org/abs/2510.11861

Impact of facility timing and coordination for next-generation gravitational-wave detectors
While the Einstein Telescope and Cosmic Explorer proposals for next-generation, ground-based detectors promise vastly improved sensitivities to gravitational-wave signals, only joint observations are expected to enable the full scientific potential of these facilities, making timing and coordination between the efforts crucial to avoid missed opportunities. This study investigates the impact of long-term delays on the scientific capabilities of next-generation detector networks. We use the Fish…

Shift vector symmetry in the Alcubierre warp drive spacetime geometry
Osvaldo L. Santos-Pereira, Everton M. C. Abreu, Marcelo B. Ribeiro
https://arxiv.org/abs/2510.11836 https:/…

Shift vector symmetry in the Alcubierre warp drive spacetime geometry
This work explores the set of coupled partial differential equations of the Einstein equations yielding vacuum solutions in the original Alcubierre warp drive metric with the cosmological constant. It is shown that under an appropriate ansatz they reveal a Burgers-type equation and a heat-type equation. These results indicate that the spacetime distortion carrying a mass particle at superluminal speeds, the Alcubierre warp bubble, may be interpreted as a geometric analog of a propagating shock …

Finite-temperature phase diagram and collective modes of coherently coupled Bose mixtures
Sunilkumar V, Rajat, Sandeep Gautam, Arko Roy
https://arxiv.org/abs/2510.11671 https:/…

Finite-temperature phase diagram and collective modes of coherently coupled Bose mixtures
We investigate the ferromagnetic-paramagnetic phase transition in coherently (Rabi) coupled Bose-Einstein condensates at zero and finite temperatures, exploring different routes to the transition by tuning the Rabi coupling or increasing the temperature at a fixed coupling. Using the Hartree-Fock-Bogoliubov theory within the Popov approximation, we map out the finite-temperature phase diagram of a three-dimensional homogeneous condensate and identify the critical line through the softening of t…

Mass-Centered GCM Framework in Perturbations of Kerr(-Newman)
Allen Juntao Fang, Elena Giorgi, Jingbo Wan
https://arxiv.org/abs/2510.10811 https://arxiv.or…

Mass-Centered GCM Framework in Perturbations of Kerr(-Newman)
The nonlinear stability problem for black hole solutions of the Einstein equations critically depends on choosing an appropriate geometric gauge. In the vacuum setting, the use of Generally Covariant Modulated (GCM) spheres and hypersurfaces has played a central role in the proof of stability for slowly rotating Kerr spacetime. In this work, we develop an alternative GCM framework, that we call mass-centered, designed to overcome the breakdown of the standard GCM construction in the charged cas…

Seed models in scalar field cosmology
I. V. Fomin
https://arxiv.org/abs/2510.06724 https://arxiv.org/pdf/2510.06724…

Seed models in scalar field cosmology
The correspondence of single-field cosmological models based on Einstein gravity to modern observational data is considered. A method is proposed to determine possible types of dynamics based on extreme values of the scalar field. It is shown that within the framework of this approach, it is possible to obtain a limited class of known inflationary models at early times. It is also shown that on large times the proposed approach leads to the $Λ$CDM--model in order to describe the dynamics of th…

Roton-mediated soliton bound states in binary dipolar condensates
R. M. V. R\"ohrs, R. N. Bisset
https://arxiv.org/abs/2510.03796 https://arxiv.org/pd…

Roton-mediated soliton bound states in binary dipolar condensates
We investigate the formation of bound states between dark-antidark solitary waves in two-component dipolar Bose-Einstein condensates. The excitation spectrum contains density and spin branches, and a rotonic feature of the spin branch enables long-range soliton interactions, giving rise to multiple bound states for a single pair, each with a distinct separation. We show that these bound states originate from periodic modulations of the inter-soliton potential, while individual solitons are surr…

A physically interesting singularity in general relativity
Bob Holdom
https://arxiv.org/abs/2510.09506 https://arxiv.org/pdf/2510.09506

A physically interesting singularity in general relativity
We explore what appears to be a very benign timelike and naked singularity of the Weyl curvature scalar. This singularity arises in an inhomogeneous generalization of the Einstein static universe. The matter energy density is everywhere finite and it vanishes at the singularity. The spacetime still enjoys causal geodesic completeness and unambiguous wave dynamics. Each singularity contributes to the Komar mass of the spacetime, and this reduces the required size of the positive cosmological con…

Physical Existence of Relativistic Stellar Models within the context of Anisotropic Matter Distribution
M. Sharif, Tayyab Naseer, Hira Shadab
https://arxiv.org/abs/2510.07362 ht…

Physical Existence of Relativistic Stellar Models within the context of Anisotropic Matter Distribution
Two distinct non-singular interior models that describe anisotropic spherical configurations are presented in this work. We develop the Einstein field equations and the associated mass function in accordance with a static spherical spacetime. We then discuss certain requirements that must be satisfied for compact models to be physically validated. Two distinct limitations are taken into account to solve the field equations, including different forms of the radial geometric component and anisotr…

Crosslisted article(s) found for cond-mat.quant-gas. https://arxiv.org/list/cond-mat.quant-gas/new
[1/1]:
- A century of the Bose-Einstein condensation concept and half a century of the JINR experiments fo...
Valentin Zagrebnov (I2M)

Replaced article(s) found for gr-qc. https://arxiv.org/list/gr-qc/new
[1/2]:
- The emergence of Einstein gravity from topological supergravity in $3 1$D
Tianyao Fang, Zheng-Cheng Gu

Replaced article(s) found for cond-mat.quant-gas. https://arxiv.org/list/cond-mat.quant-gas/new
[1/1]:
- Collective modes of two-species Bose-Einstein condensates in a Josephson junction barrier
Harsimranjit Kaur, Kuldeep Suthar

Weakly turbulent saturation of the nonlinear scalar ergoregion instability
Nils Siemonsen
https://arxiv.org/abs/2510.07467 https://arxiv.org/pdf/2510.07467…

Weakly turbulent saturation of the nonlinear scalar ergoregion instability
We perform time-domain evolutions of the ergoregion instability on a horizonless spinning ultracompact spacetime in scalar theories with potential-type and derivative self-interactions mimicking the nonlinear structure of the Einstein equations. We find that the instability saturates by triggering a weakly turbulent direct cascade, which transfers energy from the most unstable and large-scale modes to small scales. The cascade's nonlinear timescales of each mode are orders of magnitude shorter …

Scattering of massive neutrino test fields from a gravitational pulse
Tekin Dereli, Yorgo Senikoglu
https://arxiv.org/abs/2510.04687 https://arxiv.org/pdf/…

Scattering of massive neutrino test fields from a gravitational pulse
Linearized Einstein-Weyl equations are solved precisely in the context of sandwich gravitational waves. The neutrino's energy-momentum depends on the geometry and composition of the gravitational pulse when it is scattered. Since the background remains unchanged at the test field level, the neutrino's energy density will exhibit fluctuations between positive and negative extremes when traversing the sandwich wave. These variations could provide insights into the behavior of models concerning ne…

Do Black Holes Exist?
Leonardo Modesto, Edoardo Rattu
https://arxiv.org/abs/2510.04165 https://arxiv.org/pdf/2510.04165

Do Black Holes Exist?
We carefully investigate, extend, and shed new light on the McVittie exact solution of Einstein's gravity (EG) with the focus on the implications in the Universe we live in. It turns out that the only known exact solution of EG, which interpolates between an asymptotic homogeneous and isotropic Universe and a Schwarzschild black hole, is actually singular in 2M, namely, the curvature invariants diverge and the spacetime is geodetically incomplete in 2M. Very important: all energy conditions are…

Regular black holes and boson stars in semiclassical gravity
Irfan Javed, Viqar Husain
https://arxiv.org/abs/2510.03935 https://arxiv.org/pdf/2510.03935

Regular black holes and boson stars in semiclassical gravity
We use a Hamiltonian version of the semiclassical Einstein equation to study classical gravity coupled to a quantum scalar field with potential in spherical symmetry. The system is defined by effective constraints where the matter terms are replaced by their expectation values in a quantum state. For the static case, we find numerically that the resulting equations admit asymptotically flat, de Sitter, and anti-de Sitter boson star and regular black hole solutions. We also show that the Bardeen…

Can One Model Gravitational Nonlinear Memory with Fractional Derivative Operators?
Sercan Kaya, Bayram Tekin
https://arxiv.org/abs/2510.07232 https://arxiv…

Can One Model Gravitational Nonlinear Memory with Fractional Derivative Operators?
We investigate whether fractional calculus, with its intrinsic long-tailed memory and nonlocal features, can provide a viable model for gravitational-wave memory effects. We consider two toy constructions: ($i$) a fractional modification of the linearized Einstein field equations using a sequential Caputo operator, and ($ii$) a fractionalized quadrupole formula where the source moment is acted upon by the same operator. Both constructions yield history-dependent responses with small memory-like…

New charged dynamical particles in spatially flat FLRW space-times
Ion I. Cotaescu
https://arxiv.org/abs/2510.03444 https://arxiv.org/pdf/2510.03444…

New charged dynamical particles in spatially flat FLRW space-times
New time-dependent metric tensors with spherical symmetry satisfying the Einstein-Maxwell equations in space-times with FLRW asymptotic behaviour are derived here for the first time. These geometries describe dynamical charged non-rotating black holes hosted by the perfect fluid of the asymptotic FLRW space-times. Their gravitational sources are the stress-energy tensors formed by a contribution of the perfect fluid and an electromagnetic one due to the Coulomb field produced by the time-depend…

A comprehensive look into the accuracy of SpEC binary black hole waveforms
Taylor Knapp, Katerina Chatziioannou, Keefe Mitman, Mark A. Scheel, Michael Boyle, Lawrence E. Kidder, Harald Pfeiffer
https://arxiv.org/abs/2510.06393

A comprehensive look into the accuracy of SpEC binary black hole waveforms
Numerical relativity simulations provide a full description of the dynamics of binary systems, including gravitational radiation. The waveforms produced by these simulations have a number of applications in gravitational-wave detection and inference. In this work, we revisit the accuracy of the waveforms produced by the Spectral Einstein Code. Motivated by the wide range of waveform applications, we propose and explore three accuracy metrics between simulation resolutions: (i) the generalized f…