Fri·May 30, 2025Friday·May 30, 2025

1. 01*

   Current-current operator contribution to the decay matrix in $B$-meson mixing at next-to-next-to-leading order of QCD

   Marvin Gerlach🇩🇪 · Ulrich Nierste🇩🇪 · Pascal Reeck🇩🇪 · Vladyslav Shtabovenko🇩🇪 · Matthias Steinhauser🇩🇪

   We compute next-to-next-to-leading order perturbative corrections to the decay width difference of mass eigenstates and the charge-parity asymmetry $a_{\mathrm{fs}}$ in flavour-specific decays of neutral $B$ mesons. In our calculation we take into account the full dependence on the charm and bottom quark masses for the current-current operator contributions up to three-loop order. Special emphasis is put on the proper construction of the so-called $|\Delta B|=2$ theory such that Fierz symmetry is preserved. We provide updated phenomenological predictions, for $\Delta \Gamma$, $\Delta \Gamma /\Delta M$ and $a_{\mathrm{fs}}$ for the $B_d$ and $B_s$ system, including a detailed analysis of the uncertainties of our predictions. The calculated NNLO correction reduce the perturbative uncertainty of the leading term of the $1/m_b$ expansion of the width difference ${\text{dg}}_s$ in the $B_s$ system to the level of the current experimental error. The uncertainty of our prediction ${\text{dg}}_s=(0.077\pm 0.016)\text{mbox}{ps}^{-1}$ is dominated by the sub-leading term of this expansion. We further illustrate how better future measurements of ${\text{dg}}_d$ and $a_{\mathrm{fs}}^d$ will help to gain a better understanding of $B_d$-${\bar{B}}_d$ mixing.

   hep-phJHEP(2025)·6 citations
2. 02*

   A complex logistic equation for universal energy evolution in hadronic elastic scattering

   Anderson Kendi Kohara🇫🇷

   We introduce a universal evolution equation for elastic scattering of hadrons, derived from Regge Field Theory (RFT) and solved in closed analytical form. The equation has a complex logistic structure and evolves initial amplitude profiles from existing models at a fixed energy, reproducing both differential cross sections and integrated quantities over a broad energy range. It admits a unique solution for each initial condition and rigorously satisfies unitarity, the Froissart--Martin bound, and dispersion relations. The dynamics are governed by two physically meaningful parameters: the effective Pomeron mass ${ϵ}_{\mathcal{P}}$ and the nonlinear coupling $\lambda$, both fitted at a single energy. By decoupling the nonperturbative input from the universal energy evolution, the framework enables model-independent extrapolations and provides a minimal predictive alternative to eikonal resummation. Moreover, the structure of the equation -- featuring rapidity evolution, saturation, and impact-parameter dependence -- shares qualitative features with nonlinear QCD equations at small-$x$, such as BK and JIMWLK, suggesting a possible bridge between Regge-based and QCD-based approaches to high-energy scattering.

   hep-phhep-th0 citations
3. 03*

   `Dark' Matter Effect as a Novel Solution to the KM3-230213A Puzzle

   P. S. Bhupal Dev🇺🇸 · Bhaskar Dutta🇺🇸 · Aparajitha Karthikeyan🇺🇸 · Writasree Maitra🇺🇸 · Louis E. Strigari🇺🇸 · Ankur Verma🇺🇸

   The recent KM3NeT observation of an $\mathcal{O}(100\mathrm{PeV})$ event KM3-230213A is puzzling because IceCube with much larger effective area times exposure has not found any such events. We propose a novel solution to this conundrum in terms of dark matter (DM) scattering in the Earth's crust. We show that intermediate dark-sector particles that decay into muons are copiously produced when high-energy ($\sim 100\text{PeV}$) DM propagates through a sufficient amount of Earth overburden. The same interactions responsible for DM scattering in Earth also source the boosted DM flux from a high-luminosity blazar. We address the non-observation of similar events at IceCube via two examples of weakly coupled long-lived dark sector scenarios that satisfy all existing constraints. We calculate the corresponding dark sector cross sections, lifetimes and blazar luminosities required to yield one event at KM3NeT, and also predict the number of IceCube events for these parameters that can be tested very soon. Our proposed DM explanation of the event can also be distinguished from a neutrino-induced event in future high-energy neutrino flavor analyses, large-scale DM direct detection experiments, as well as at future colliders.

   hep-phastro-ph.HE28 citations
4. 04*

   Odderon Exchange in Elastic Proton-Proton and Proton-Antiproton Scattering at TeV Energies

   István Szanyi🇭🇺

   The odderon, a leading crossing-odd $t$-channel exchange, was first proposed by L. Lukaszuk and B. Nicolescu in 1973, but its existence remained elusive for 48 years. Elastic proton-proton scattering measurements at CERN's Large Hadron Collider (LHC) and elastic proton-antiproton scattering measurements at FNAL's Tevatron, performed at TeV-scale center-of-mass energies ($\sqrt{s}$) and over wide ranges of squared four-momentum transfer ($t$), opened new opportunities to study the physics of elastic hadronic processes which ultimately led to the discovery of odderon exchange in the nonperturbative domain of strong interactions, as detailed in this dissertation. In quantum chromodynamics (QCD), the fundamental theory of strong interactions, the odderon is described in the perturbative regime as a $t$-channel exchange of an odd number of interacting gluons.

   hep-ph0 citations
5. 05*

   Can we live in a baby universe formed by a delayed first-order phase transition?

   Qing-Hong Cao🇨🇳 · Masanori Tanaka🇨🇳 · Jun-Chen Wang🇨🇳 · Ke-Pan Xie🇨🇳 · Jing-Jun Zhang🇨🇳

   We examine the idea that our universe began as a baby universe and show that this is feasible in a gauged $U(1{)}_{B-L}$ extension of the Standard Model with the classically conformal principle. For the first time, we define a measure to describe the probability that we reside in a baby universe, and find that it can be close to 1 in a considerable portion of the parameter space. The framework is consistent with current cosmological data, and it predicts the existence of a heavy neutral gauge boson, which could be detected at colliders, thereby offering a direct link between early-universe dynamics and experimentally testable signatures at the TeV scale.

   hep-phgr-qcPRD(2026)·6 citations
6. 06*

   Effects of bottom quark induced processes on polarized $W^{+}{W}^{-}$ production at the LHC at NLO

   Duc Ninh Le🇻🇳 · Thi Nhung Dao🇻🇳

   In this report we discuss the definition of the polarized cross sections of the inclusive $W^{+}{W}^{-}$ production at the LHC. Results at the level of next-to-leading order (NLO) QCD+EW accuracy, published in our recent paper, are presented to highlight the effects of bottom-quark induced processes. Compared to the unpolarized case, the bottom-induced effects after the subtraction of the on-shell top-quark contribution are more sizable for the doubly-longitudinal polarization.

   hep-phhep-exJ.Phys.Conf.Ser.(2025)·0 citations
7. 07*

   Kinetically Modified Palatini Inflation Meets ACT Data

   C. Pallis🇬🇷

   We show that the coexistence of a non-minimal coupling to gravity $f_{\mathcal{R}}=1+c_{\mathcal{R}}{\varphi }^{n/2}$ with a kinetic mixing of the form $f_K=f_{\mathcal{R}}^m$ -- where $n=2$ and $4$ and $0.5\le m\le 10$ -- reconciles chaotic inflation based on the ${\varphi }^n$ potential with the recent ACT results, if we adopt the Palatini formulation of gravity. The attainment of inflation allows for subplanckian inflaton values and energy scales below the cut-off scale of the corresponding effective theory. The model can be also embedded in supergravity by introducing two chiral superfields and a monomial superpotential, linear with respect to the inflaton-accompanying field. Its stabilization is achieved thanks to a compact contribution to the Kaehler potential, whose the inflationary part includes an holomorphic logarithmic term and a real one multiplying a shift-symmetric quadratic polynomial term.

   hep-phastro-ph.COhep-thPLB(2025)·45 citations
8. 08*

   Dark clouds to silver linings over the hyperchargeless scalar triplets

   Priyotosh Bandyopadhyay🇮🇳 · Snehashis Parashar🇮🇳

   A real scalar triplet with zero hypercharge offers a minimal non-trivial extension of the Standard Model (SM) with a charged Higgs and a possible dark matter or custodial symmetry breaking signature. The $Z_2$-odd inert triplet model (ITM) provides a dark matter, while the non-inert Higgs triplet model (HTM) breaks the custodial symmetry, enabling rich collider signatures. Both these models also promise the viability of a first-order phase transition (FOPT). This letter revisits both models under various theoretical and current experimental constraints, revealing a trade-off between DM and FOPT viability, and explores the resulting gravitational wave signals and collider prospects.

   hep-phPRD(2025)·2 citations
9. 09*

   Neutrinos from Primordial Black Holes in Theories with Extra Dimensions

   Luis A. Anchordoqui🇺🇸 · Francis Halzen🇺🇸 · Dieter Lust🇩🇪

   The quantum gravity scale within the dark dimension scenario ($M_{\ast }\sim 10^9\mathrm{GeV}$) roughly coincides with the energy scale of the KM3-230213A neutrino ($E_{\nu }\sim 10^8\mathrm{GeV}$). We propose an interpretation for this intriguing coincidence in terms of Hawking evaporation of five-dimensional (5D) primordial black holes (PBHs). 5D PBHs are bigger, colder, and longer-lived than 4D PBHs of the same mass. For brane observers, PBHs residing in the higher-dimensional bulk decay essentially invisibly (only through gravitationally and sterile coupled modes). As a consequence, constraints on the density of PBHs relative to that of dark matter from null searches of Hawking evaporation can be avoided. We demonstrate that Hawking evaporation of 5D bulk PBHs can explain the KM3-230213A neutrino, evade constraints from upper limits on the gamma-ray flux, and remain consistent with IceCube upper limits on the partial decay width of superheavy dark matter particles into neutrinos.

   hep-phPRD(2025)·27 citations
10. 10*

    Pion Phenomenology from the Thermal Soft-Wall Model of Holographic QCD

    Narmin Nasibova🇦🇿 · Xerxes D. Arsiwalla🇺🇸

    Within the framework of the thermal soft-wall model of AdS/QCD, we investigate phenomenological properties of pions at finite temperature. This includes the electromagnetic (EM) form factor $F_{\pi }(Q^2,T)$, the thermal mass $M_{\pi }(T)$, charge radius $r_{\pi }(T)$, the generalized parton distribution (GPD) $H_{\pi }(x,Q^2,T)$, the charge density ${\rho }_{\pi }(b,T)$ of the pion, the pion-nucleon coupling constant $g_{\pi NN}(T)$, and pion-$\Delta$ baryon coupling constant $g_{\pi \Delta \Delta }(T)$ coupling constant at finite temperature. The thermal pion form factor is extrapolated from the zero-temperature case. Subsequently, the GPD is obtained at finite temperature from this form factor. The above-mentioned quantities were analyzed using a thermal dilaton field in the five-dimensional AdS action. Moreover, we determine the theoretical expression for the temperature-dependent pion-nucleon coupling constant, and the pion-$\Delta$ baryon coupling constant using thermal profile functions of the nucleon, $\Delta$ baryon and the pion. Our results show that the values of these quantities decrease with increasing temperature and vanish near the critical temperature $T_c$; except for the pion radius, which diverges at $T_c$. Our results reproduce expected features of low-energy hadron dynamics, thus validating the phenomenological utility of the thermal soft-wall model.

    hep-phPRD(2025)·3 citations
11. 11*

    Factorized QED and QCD Contribution to Deeply Inelastic Scattering

    Justin Cammarota🇺🇸 · Jian-Wei Qiu🇺🇸 · Kazuhiro Watanabe🇯🇵 · Jia-Yue Zhang🇺🇸

    We present the first calculation of next-to-leading order (NLO) factorized QED and QCD contributions to the short-distance hard coefficients of inclusive lepton-hadron deep inelastic scattering (DIS) in a joint QED and QCD factorization approach. Unlike the traditional radiative correction approach to handle the collision-induced QED contributions to DIS, QED radiation from all charged leptons and quarks are treated equally, and their collinear sensitivities are systematically factorized into corresponding universal lepton and parton distribution functions. We demonstrate that the NLO factorized QED contribution is completely infrared safe and calculable without the need of any parameters other than the standard factorization scale in the same way as the factorized QCD contribution. We discuss the potential impact of this joint factorization approach on the extraction of partonic information from lepton-hadron DIS.

    hep-phhep-exnucl-exnucl-thPRD(2025)·10 citations
12. 12*

    Charged particle multiplicity distributions derived from the Principle of Maximal Entropy

    Sándor Lökös🇵🇱

    Recent theoretical results renewed the interest in charged particle multiplicity distributions. The Shannon entropy of such distributions is conjectured to be related to the entanglement or von Neumann entropy of partonic quantum system. In this paper, we show that the measured charged particle multiplicities can be derived from the principle of maximum entropy (POME or MAXENT) without any a priori physical assumption. The approach provides a natural explanation for the well-known negative binomial shape of the measured distributions.

    hep-phActa Phys.Polon.Supp.(2025)·5 citations
13. 13*

    Electroexcitation of Nucleon Resonances and the Emergence of Hadron Mass

    Patrick Achenbach🇺🇸 · Daniel S. Carman🇺🇸 · Ralf W. Gothe🇺🇸 · Kyungseon Joo🇺🇸 · Victor I. Mokeev🇺🇸 · Craig D. Roberts🇨🇳

    Developing an understanding of phenomena driven by the emergence of hadron mass (EHM) is one of the most challenging problems in the Standard Model. This discussion focuses on the impact of results on nucleon resonance ($N^{\ast }$) electroexcitation amplitudes (or ${\gamma }_{v}p{N}^{\ast }$ electrocouplings) obtained from experiments during the 6-GeV era in Hall~B at Jefferson Lab on understanding EHM. Analyzed using continuum Schwinger function methods (CSMs), these results have revealed new pathways for the elucidation of EHM. A good description of the $\Delta (1232)3/2^{+}$, $N(1440)1/2^{+}$, and $\Delta (1600)3/2^{+}$ electrocouplings, achieved by CSM analyses that express a realistic dressed quark mass function, sheds light on the strong interaction dynamics that underlies EHM. Extensions to nucleon resonance studies for higher-mass states are outlined, as well as experimental results anticipated in the 12-GeV era at Jefferson Lab and those that would be enabled by a further increase of the beam energy to 22~GeV.

    hep-phnucl-exnucl-thSymmetry(2025)·23 citations
14. 14*

    Physics beyond the Standard Model with the DSA-2000

    Kim V. Berghaus🇺🇸 · Yufeng Du🇺🇸 · Vincent S. H. Lee🇺🇸 · Anirudh Prabhu🇺🇸 · Robert Reischke🇩🇪 · Liam Connor🇺🇸 · Kathryn M. Zurek🇺🇸

    The upcoming Deep Synoptic Array 2000 (DSA-2000) will map the radio sky at $0.7-2$ GHz ($2.9-8.3\mu$eV) with unprecedented sensitivity. This will enable searches for dark matter and other physics beyond the Standard Model, of which we study four cases: axions, dark photons, dark matter subhalos and neutrino masses. We forecast DSA-2000's potential to detect axions through two mechanisms in neutron star magnetospheres: photon conversion of axion dark matter and radio emission from axion clouds, developing the first analytical treatment of the latter. We also forecast DSA-2000's sensitivity to discover kinetically mixed dark photons from black hole superradiance, constrain dark matter substructure and fifth forces through pulsar timing, and improve cosmological neutrino mass inference through fast radio burst dispersion measurements. Our analysis indicates that in its planned five year run the DSA-2000 could reach sensitivity to QCD axion parameters, improve current limits on compact dark matter by an order of magnitude, and enhance cosmological weak lensing neutrino mass constraints by a factor of three.

    hep-phastro-ph.COJCAP(2025)·8 citations
15. 15*

    Probability of the Initial Conditions for Inflation and Slow Contraction

    Mark P. Hertzberg🇺🇸 · Daniel Jiménez-Aguilar🇺🇸

    Some recent studies based on numerical relativity simulations claim that slow contraction/ekpyrosis is strongly preferred over inflation as the smoothing mechanism that brought the universe into the homogeneous, isotropic and flat state we observe today on large scales. In this paper, we evaluate the likelihood of the initial conditions employed in the aforementioned simulations by estimating the probability that a free scalar field dominating the universe at the beginning of inflation or ekpyrosis will be sufficiently homogeneous on scales comparable to the Hubble radius at that time. We explore the space of parameters that characterize the initial power spectrum of the scalar field, finding that either can be more likely than the other for a fixed choice of parameters. On the other hand, when we extremize over these parameters, we find that the maximal probability for inflation is much higher than that of ekpyrosis.

    ↳ gr-qcastro-ph.COhep-phhep-thPRD(2025)·1 citation
16. 16*

    Forecasting Constraints on Non-Thermal Light Massive Relics from Future CMB Experiments (CMB-S4/Simons Observatory)

    Arka Banerjee🇮🇳 · Abhik Bhattacharjee🇮🇳 · Subinoy Das🇮🇳 · Anshuman Maharana🇮🇳 · Ravi Kumar Sharma🇩🇪

    In this work we present Fisher forecasts on \textit{non-thermal LiMR} models for a CMB Stage IV-like experiment and the Simons Observatory -- particularly focusing on a model of inflaton/moduli decay giving rise to non-thermally distributed dark sector particles, and also comparing our results with those for sterile particles following the Dodelson-Widrow distribution. Two independent parameters, $\Delta N_{\mathrm{eff}}$ and $M_{\mathrm{sp}}^{\mathrm{eff}}$, influence linear cosmological observables. We find $\Delta N_{\mathrm{eff}}$ to be more tightly constrained (by a factor of $10$) for a less abundant, heavier LiMR which becomes fully non-relativistic around matter-radiation equality than a more abundant, lighter LiMR which becomes fully non-relativistic just after recombination. The uncertainties on $M_{\mathrm{sp}}^{\mathrm{eff}}$ differ by a factor of $\sim 3$ between the two cases. Our analysis also reveals distinct parameter correlations: the phenomenological parameters $\{\Delta N_{\mathrm{eff}},M_{\mathrm{sp}}^{\mathrm{eff}}\}$ are found to be negatively correlated for the former case and positively correlated for the latter. We obtain similar projected uncertainties on the cosmological parameters (in either case) for both the inflaton/moduli decay and the Dodelson-Widrow models when the first two moments of the LiMR distribution function, related to the phenomenological parameters, are matched. Finally, by constructing a modified distribution that matches the first two moments of the Dodelson-Widrow but deviates maximally in the third moment, we demonstrate that CMB Stage IV data is not expected to be sensitive to higher moments of the distribution.

    ↳ astro-ph.COhep-phPRD(2026)·5 citations
17. 17*

    Window observables for benchmarking parton distribution functions

    Joe Karpie🇺🇸 · Christopher J. Monahan🇺🇸 · Kostas Orginos🇺🇸 · Savvas Zafeiropoulos🇫🇷

    Global analysis of collider and fixed-target experimental data and calculations from lattice quantum chromodynamics (QCD) are used to gain complementary information on the structure of hadrons. We propose novel ``window observables'' that allow for higher precision cross-validation between the different approaches, a critical step for studies that wish to combine the datasets. Global analyses are limited by the kinematic regions accessible to experiment, particularly in a range of Bjorken-$x$, and lattice QCD calculations also have limitations requiring extrapolations to obtain the parton distributions. We provide two different ``window observables'' that can be defined within a region of $x$ where extrapolations and interpolations in global analyses remain reliable and where lattice QCD results retain sensitivity and precision.

    ↳ hep-lathep-phPRL(2025)·2 citations
18. 18*

    Electron-positron pair annihilation in kinetic plasma

    Haidar Al-Naseri🇺🇸

    The process of electron positron pair annihilation, driven by strong fields (Inverse Schwinger mechanism) and high-frequency waves, is studied using the Dirac Heisenberg Wigner formalism. In an electron positron plasma, the presence of a strong field leads to both pair creation and annihilation. Depending on plasma properties such as non-degeneracy and the momentum distribution, pair annihilation can dominate over pair creation. The energy released from annihilated pairs can lead to an enhancement of the field energy, provided that the plasma effectively blocks the creation of new pairs. Additionally, pair annihilation induced by high-frequency waves is shown to occur when the photon energy matches the energy of the pairs in the plasma.

    ↳ physics.plasm-phhep-phhep-thPhys.Plasmas(2025)·1 citation
19. 19*

    Condensates, crystals, and renormalons in the Gross-Neveu model at finite density

    Francesco Benini🇮🇹 · Ohad Mamroud🇮🇹 · Tomas Reis🇮🇹 · Marco Serone🇮🇹

    We study the $O(2N)$ symmetric Gross-Neveu model at finite density in the presence of a $U(1)$ chemical potential $h$ for a generic number $a\le N-2$ of fermion fields. By combining perturbative quantum field theory, semiclassical large $N$, and Bethe ansatz techniques, we show that at finite $N$ two new dynamically generated scales ${\Lambda }_{\mathrm{n}}$ and ${\Lambda }_{\mathrm{c}}$ appear in the theory, governing the mass gap of neutral and charged fermions, respectively. Above a certain threshold value for $h$, $a$-fermion bound states condense and form an inhomogeneous configuration, which at infinite $N$ is a crystal spontaneously breaking translations. At large $h$, this crystal has mean ${\Lambda }_{\mathrm{n}}$ and spatial oscillations of amplitude $2{\Lambda }_{\mathrm{c}}$. The two scales also control the nonperturbative corrections to the free energy, resolving a puzzle concerning fractional-power renormalons and predicting new ones.

    ↳ hep-thcond-mat.stat-mechcond-mat.str-elhep-lat+1PRL(2025)·5 citations
20. 20*

    Constraining primordial curvature perturbations with present and future GW detectors

    Mauro Pieroni🇨🇭

    Primordial scalar curvature perturbations ($\zeta$), typically probed on large cosmological scales via CMB and LSS observations, can be significantly enhanced on smaller scales by various early Universe mechanisms, for instance, non-minimal inflationary models. While decoupled at linear order, scalar and tensor perturbations, i.e., Gravitational Waves (GWs), interact at second order. As a consequence, an enhanced primordial scalar power spectrum $P_{\zeta }(k)$ can source a sizable stochastic GW background (SGWB). In these proceedings, we briefly review the generation mechanism of such signals, typically referred to as scalar-induced GWs (SIGWs), and discuss the prospects of measuring them with present and future Pulsar Timing Arrays datasets and future GW observatories like the Laser Interferometer Space Antenna LISA.

    ↳ astro-ph.COastro-ph.HEgr-qchep-ph+10 citations
21. 21*

    Colloquium: The Cosmic Dipole Anomaly

    Nathan Secrest🇺🇸 · Sebastian von Hausegger🇬🇧 · Mohamed Rameez🇮🇳 · Roya Mohayaee🇫🇷 · Subir Sarkar🇬🇧

    The Cosmological Principle, which states that the Universe is homogeneous and isotropic (when averaged on large scales), is the foundational assumption of Friedmann-Lemaitre-Robertson-Walker (FLRW) cosmologies such as the current standard Lambda-Cold-Dark-Matter ({\Lambda}CDM) model. This simplification yields an exact solution to the Einstein field equations that relates space and time through a single time-dependent scale factor, which defines cosmological observables such as the Hubble parameter and the cosmological redshift. The validity of the Cosmological Principle, which underpins modern cosmology, can now be rigorously tested with the advent of large, nearly all-sky catalogs of radio galaxies and quasars. Surprisingly, the dipole anisotropy in the large-scale distribution of matter is found to be inconsistent with the expectation from kinematic aberration and Doppler boosting effects in a perturbed FLRW universe, which is the standard interpretation of the observed dipole in the cosmic microwave background (CMB). Although the matter dipole agrees in direction with that of the CMB dipole, it is anomalously larger, demonstrating that either the rest frames in which matter and radiation appear isotropic are not the same, or that there is an unexpected intrinsic anisotropy in at least one of them. This discrepancy now exceeds 5{\sigma} in significance. We review these recent findings, as well as the potential biases, systematic issues, and alternate interpretations that have been suggested to help alleviate the tension. We conclude that the cosmic dipole anomaly poses a serious challenge to FLRW cosmology, and the standard {\Lambda}CDM model in particular, as an adequate description of our Universe.

    ↳ astro-ph.COgr-qchep-phRMP(2025)·42 citations
22. 22*

    Neutron Stars in Causal Scalar-Tensor Theories

    Mark P. Hertzberg🇺🇸 · Oleksandr S. Stashko🇺🇸

    We study static, spherically symmetric neutron stars in a class of scalar-tensor theories with non-canonical kinetic terms (K-essence) obeying all causality and hyperbolicity conditions. These models have non-trivial dynamics that lead to a type of anti-screening of the scalar. They lead to small corrections in the solar system due to a small coupling, but can lead to large corrections in regimes of high densities, especially neutron stars. We solve the modified Tolman-Oppenheimer-Volkoff equations numerically using realistic equations of state (SLy4, WFF1, MS1, MPA1). For a given central density, we find that two distinct configurations may exist, forming two separate branches of solutions. We find that above a certain critical central density solutions with the correct asymptotic behavior at spatial infinity cannot be obtained. We obtain precise predictions for the mass-radius relation for neutron stars for different values of the parameters in the model and we compare to data.

    ↳ gr-qcastro-ph.COhep-phhep-thPRD(2025)·1 citation
23. 23*

    Black hole spectroscopy: from theory to experiment

    Emanuele Berti🇺🇸 · Vitor Cardoso🇩🇰 · Gregorio Carullo🇩🇰 · Jahed Abedi🇨🇳 · Niayesh Afshordi🇨🇦 · Simone Albanesi🇩🇪 · Vishal Baibhav🇺🇸 · Swetha Bhagwat🇬🇧 · José Luis Blázquez-Salcedo🇪🇸 · Béatrice Bonga🇳🇱 · Bruno Bucciotti🇮🇹 · Giada Caneva Santoro🇪🇸 and 56 other authors

    The "ringdown" radiation emitted by oscillating black holes has great scientific potential. By carefully predicting the frequencies and amplitudes of black hole quasinormal modes and comparing them with gravitational-wave data from compact binary mergers we can advance our understanding of the two-body problem in general relativity, verify the predictions of the theory in the regime of strong and dynamical gravitational fields, and search for physics beyond the Standard Model or new gravitational degrees of freedom. We summarize the state of the art in our understanding of black hole quasinormal modes in general relativity and modified gravity, their excitation, and the modeling of ringdown waveforms. We also review the status of LIGO-Virgo-KAGRA ringdown observations, data analysis techniques, and the bright prospects of the field in the era of LISA and next-generation ground-based gravitational-wave detectors.

    ↳ gr-qcastro-ph.HEhep-phClass.Quant.Grav.(2026)·311 citations
24. 24*

    Superfluid Dark Matter

    Lasha Berezhiani🇩🇪 · Giordano Cintia🇮🇹 · Valerio De Luca🇺🇸 · Justin Khoury🇺🇸

    The superfluid dark matter model offers an elegant solution to reconcile discrepancies between the predictions of the cold dark matter paradigm and observations on galactic scales. In this scenario, dark matter is composed of ultralight bosons with self-interactions that can undergo a superfluid phase transition in galactic environments. In this review, we explore the theoretical foundations of dark matter superfluidity, detailing the conditions required for the formation and stability of superfluid cores of astrophysical size. We examine the phenomenological consequences for galactic dynamics, including the impact on galaxy mergers, the formation of vortices, the behavior near supermassive black holes, modifications to dynamical friction, and the emergence of long-range interactions. By synthesizing theoretical developments with observational constraints, we aim to provide a comprehensive overview of the current status and future prospects of dark matter superfluidity as a viable extension of the standard cosmological model.

    ↳ astro-ph.COgr-qchep-phhep-thPhys.Rept.(2026)·14 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.