Fri·Oct 11, 2024Friday·October 11, 2024

1. 01*

   Formation of defects associated with both spontaneous and explicit symmetry breaking

   Kohei Fujikura🇯🇵 · Mairi Sakellariadou🇬🇧 · Michiru Uwabo-Niibo🇯🇵 · Masahide Yamaguchi🇰🇷

   We discuss formation of cosmic strings associated with a spontaneously broken approximate $U(1)$ symmetry by performing classical field-theoretical simulations. An original $U(1)$ symmetry is explicitly broken down to its subgroup $Z_N$ even before spontaneous breaking takes place. We estimate the ratio of explicit breaking to that of spontaneous breaking for which topological defects for $N=1$ and $N=2$ are formed. For $N=1$, a cosmic string attached to a single domain wall can be formed when the amount of the explicit breaking is three orders of magnitude smaller than that of the spontaneous breaking. For $N=2$, no matter how large the explicit breaking is, domain walls are inevitably formed as long as the temperature of the Universe is high enough to restore $Z_2$ symmetry. In that case, cosmic strings are also inevitably formed as long as the amount of the explicit breaking is smaller than that of the spontaneous breaking.

   hep-phastro-ph.COhep-thPRD(2025)·2 citations
2. 02*

   Transverse and spatial structure of light to heavy pseudoscalar mesons in light-cone quark model

   Satyajit Puhan🇮🇳 · Navpreet Kaur🇮🇳 · Harleen Dahiya🇮🇳

   In this work, we have investigated the transverse and spatial structure of light (${\pi }^{+}(u\bar{d})$, $K^{+}(u\bar{s})$) and heavy (${\eta }_c(c\bar{c})$, ${\eta }_b(b\bar{b})$, $B$ and $D$) pseudoscalar mesons using the light-cone quark model. The transverse structure of these particles have been studied using the transverse momentum dependent parton distribution (TMDs). The leading twist unpolarized $f_1(x,{\mathbf{k}}_{\perp }^2)$ TMD has been solved using the quark-quark correlator. We have predicted the average momenta carried by the quark and antiquark of the considered mesons. For a complete description of mesons, we have also computed the leading twist unpolarized $H(x,0,-t)$ generalized parton distribution (GPD). Further, electromagnetic form factors (EMFFs), along with gravitational form factors (GFFs) have been derived by taking the zeroth and first moments of the unpolarized GPD. These EMFFs are found to be compatible with available lattice simulation results. Further, we have also calculated the parton distribution functions (PDFs) for both the quarks and the antiquarks of these mesons. The PDF sum rule has also been verified.

   hep-phPRD(2025)·12 citations
3. 03*

   Dark Matter Internal Pair Production -- A Novel Direct Detection Mechanism

   Bhaskar Dutta🇺🇸 · Aparajitha Karthikeyan🇺🇸 · Hyunyong Kim🇺🇸 · Mudit Rai🇺🇸

   We propose a novel mechanism, dark matter internal pair production (DIPP), to detect dark matter candidates at beam dump facilities. When energetic dark matter scatters in a material, it can create a lepton-antilepton pair by exchanging a virtual photon with the nucleus, similar to the neutrino trident process. We demonstrate this process for dark matter coupled to dark photons in experiments such as DarkQuest, SBND, and DUNE ND experiments. Since the pair-produced lepton-antilepton pair carries a large fraction of the center-of-mass energy and also has similar energy profiles, they can be clearly distinguished from backgrounds. We utilize the above features to show that DIPP is effective in probing various dark matter models, especially at DUNE ND and DarkQuest, by looking for electron-positron and muon-antimuon signatures. We also consider a scenario with dark sector couplings to quarks and muons only to show that DIPP can probe a wide range of dark matter models with various final states.

   hep-phPRL(2025)·6 citations
4. 04*

   Hidden-charm strong decays of the spin-$2$ partner of $X(3872)$

   Gurjav Ganbold🇷🇺 · M. A. Ivanov🇷🇺

   Hidden-charm strong decays of the spin-2 partner $X_2(4014)$ of the charmonium-like state $X(3872)$ have been studied in the framework of the covariant confined quark model. The exotic state $X_2$ has been interpreted as a four-quark state with molecular-type interpolating current. We have considered the decay widths of $X_2$ on the level of two-petal quark loops. The partial widths of the strong decays $X_2\to \omega J/\Psi$ and $X_2\to {\rho }^{0}J/\Psi$ have been calculated and the related branching ratio has been analyzed.

   hep-phPRD(2025)·4 citations
5. 05*

   Predictions for off-shell $t\bar{t}Z$ production at the LHC: the complete set of LO and NLO contributions

   Daniele Lombardi🇩🇪

   We present predictions for the production and decay of a top--antitop pair in association with a Z boson in the multi-lepton decay channel at the LHC. Our results include the complete set of LO and NLO contributions. Since our calculation is based on full matrix elements, off-shell effects are entirely taken into account. Integrated and differential cross-sections are reported for a realistic fiducial setup.

   hep-phSciPost Phys.Proc.(2026)·0 citations
6. 06*

   Quantifying the Jet Energy Loss in Pb+Pb collisions at LHC

   Vineet Kumar🇮🇳 · Prashant Shukla🇮🇳

   In this work, we give a method to study the energy loss of jets in the medium using a variety of jet energy loss observables such as nuclear modification factor and transverse momentum asymmetry in dijets and $\gamma$-jets in heavy ion collisions. The energy loss of jets in the medium depends mainly on the size and the properties of medium viz. temperature and is a function of energy of the jets as predicted by various models. A Monte Carlo (MC) method is employed to generate the transverse momentum and path-lengths of the initial jets that undergo energy loss. Using different scenarios of energy loss, the transverse momentum and system size dependence of nuclear modification factors and different measures of dijet momentum imbalance at energies $sqrt{s}_{\mathrm{NN}}$ = 2.76 TeV and 5.02 TeV and $\gamma$-jet asymmetry at $\sqrt{s_{\mathrm{NN}}}$ =2.76 TeV in Pb+Pb collisions are simulated. The results are compared with the measurements by ATLAS and CMS experiments as a function of transverse momentum and centrality. The study demonstrates how the system size and energy dependence of jet energy loss can be quantified using various experimental observables.

   hep-phhep-exnucl-thEPJA(2024)·1 citation
7. 07*

   An Implicit Regularization Approach to Chiral Models

   Ricardo J. C. Rosado🇵🇹 · Adriano Cherchiglia🇧🇷 · Marcos Sampaio🇧🇷 · Brigitte Hiller🇵🇹

   The decays of the Z boson and CP-even or CP-odd scalar bosons into quark-antiquark pairs have been calculated at NLO in the framework of Implicit Regularization (IReg) , which operates strictly in the physical dimension and complies with the BPHZ procedure. The presence of the {\gamma}5 matrix is dealt without the need of gauge symmetry restoring counterterms and the Kinoshita-Lee-Nauenberg (KLN) theorem is verified. The results are compared to the ones obtained in the Dimensional Reduction scheme (DRed).

   hep-phActa Phys.Polon.Supp.(2024)·2 citations
8. 08*

   Four-loop splitting functions in QCD -- The gluon-gluon case --

   G. Falcioni (Zurich U.)🇮🇹 · F. Herzog (U. Edinburgh, Higgs Ctr. Theor. Phys.)🇬🇧 · S. Moch (Hamburg U., Inst. Theor. Phys. II)🇩🇪 · A. Pelloni (Zurich, ETH)🇨🇭 · A. Vogt (Liverpool U., Dept. Math.)🇬🇧

   We have computed the even-N moments N =< 20 of the gluon-gluon splitting function P_{gg} at the fourth order of perturbative QCD via the renormalization of off-shell operator matrix elements. Our results, derived analytically for a general compact simple gauge group, agree with all results obtained for this function so far, in particular with the lowest five moments obtained via structure functions in deep-inelastic scattering. Using our new moments and all available endpoint constraints, we construct improved approximations for the four-loop P_{gg}(x) that should be sufficient for a wide range of collider-physics applications. The N^3LO contributions to the scale derivative of the gluon distribution, resulting from these and the corresponding quark-to-gluon splitting functions, amount to 1% or less at x >~ 10^{-4} at a standard reference scale with alpha_s = 0.2.

   hep-phPLB(2025)·42 citations
9. 09*

   Anatomy of Non-Leptonic Two-Body Decays of Charmed Mesons into Final States with ${\eta }^{\prime }$

   Carolina Bolognani🇳🇱 · Ulrich Nierste🇩🇪 · Stefan Schacht🇬🇧 · K. Keri Vos🇳🇱

   We show that $D\to P{\eta }^{\prime }$ decay amplitudes, where $P=K,\pi ,\eta$, cannot be simply related to their $D\to P\eta$ counterparts with a single ${\eta }_0$--${\eta }_8$ mixing angle. We propose a novel, consistent treatment of ${\eta }_0$--${\eta }_8$ mixing for application in $D\to P\eta$ and $D\to P{\eta }^{\prime }$ decays. Using this framework, we perform a global analysis of $D\to P{\eta }^{\prime }$ decays employing SU(3)${}_F$ symmetry including linear SU(3)${}_F$ breaking. We find that the assumption of 30\% SU(3)${}_F$ breaking is in slight tension ($2.5\sigma$) with the data when compared to a fit that allows for 50\% SU(3)${}_F$ breaking, the latter giving a perfect description of the data. In order to allow for further scrutinization of SU(3)${}_F$-breaking effects in the future, we give branching ratio predictions for all $D\to P{\eta }^{\prime }$ modes. Our predictions deviate from the current data in case of the branching ratios $\mathcal{B}(D_s^{+}\to K^{+}{\eta }^{\prime })$ and $\mathcal{B}(D^{+}\to K^{+}{\eta }^{\prime })$. Future more precise measurements of these channels are therefore highly important in order to clarify the quality of the SU(3)${}_F$ expansion in nonleptonic $D\to P{\eta }^{\prime }$ decays.

   hep-phhep-exJHEP(2025)·10 citations
10. 10*

    Anomalous $U(1{)}_A$ couplings and the Columbia plot

    Francesco Giacosa🇵🇱 · Győző Kovács🇭🇺 · Péter Kovács🇭🇺 · Robert D. Pisarski🇺🇸 · Fabian Rennecke🇩🇪

    When the quark masses are lighter than those in QCD, the standard lore is that a chiral transition of first order must emerge for three, light flavors. Recently, however, numerical simulations on the lattice suggest that the chiral transition is of second order in the chiral limit. Using an extended linear sigma model in the mean field approximation, we study the relation between terms which break the anomalous, $U(1{)}_A$ symmetry and the order of the chiral phase transition, especially how a chiral transition of second order can arise for three, massless flavors. We note that in an (unphysical) region of the "Columbia" phase diagram, when the strange quark mass is light and negative, corresponding to topological angle $\theta =\pi$, the $CP$ symmetry is spontaneously broken.

    hep-phhep-latnucl-thPRD(2025)·25 citations
11. 11*

    Unusual portals to new exotics, the W-gluon portal

    Linda M. Carpenter🇺🇸 · Katherine Schwind🇺🇸

    We explore models where new light exotic states interact with the Standard Model through an asymmetric di-boson portal with one gluon and one W boson. We consider the complete set of effective operators up to dimension 6 which couple a single light exotic (LEX) state to at least one W boson and 1 gluon. Other Standard Model particles may also be present in the interactions. We discover that the W-gluon portal allows us to access a large array of exotic states in non-trivial representations of SU(3) and SU(2). We discuss new single production collider modes and phenomenological signatures for these light exotic states at LHC and e-p colliders.

    hep-ph4 citations
12. 12*

    How large can the Light Quark Yukawa couplings be?

    Barbara Anna Erdelyi🇮🇹 · Ramona Gröber🇮🇹 · Nudzeim Selimovic🇮🇹

    We investigate models that can induce significant modifications to the couplings of first- and second-generation quarks with Higgs bosons. Specifically, we identify all simplified models featuring two vector-like quark states which can lead to substantial enhancements in these couplings. In addition, these models generate operators in Standard Model Effective Field Theory, both at tree-level and one-loop, that are constrained by electroweak precision and Higgs data. We show how to evade constraints from flavour physics and consider direct searches for vector-like quarks. Ultimately, we demonstrate that viable ultraviolet models can be found with first-generation quark Yukawa couplings enhanced by several hundred times their Standard Model value, while the Higgs couplings to charm (strange) quarks can be increased by factors of a few (few tens). Given the importance of electroweak precision data in constraining these models, we also discuss projections for future measurements at the Tera-$Z$ FCC-ee machine.

    hep-phhep-exJHEP(2025)·25 citations
13. 13*

    Real Singlet Scalar Benchmarks in the Multi-TeV Resonance Regime

    Ian M. Lewis🇺🇸 · Jacob Scott🇺🇸 · Miguel A. Soto Alcaraz🇺🇸 · Matthew Sullivan🇺🇸

    Scalar extensions of the Standard Model are of much interest at the LHC and future colliders. In particular, these models can give rise to resonant di-Higgs production and alter the Higgs trilinear coupling. In this paper, we study di-Higgs production in the Standard Model extended by a real scalar singlet with no additional symmetries. We determine how large the resonant di-Higgs rate and variation in the Higgs trilinear coupling can be in four scenarios: current LHC results and projected results at the HL-LHC, the HL-LHC combined with a circular $e^{-}{e}^{+}$ collider such as the CEPC or FCC-ee, and the HL-LHC combined with a linear $e^{-}{e}^{+}$ collider such as the ILC. While these are updated results from a previous study using current LHC data, we go further and find benchmark points in the multi-TeV resonance regime for future colliders beyond the HL-LHC. Considering current LHC results, the resonant di-Higgs rate can still be an order of magnitude larger than the SM predicted di-Higgs rate. In the HL-LHC scenario, the Higgs trilinear coupling can still be a factor of three larger than the SM prediction for resonance masses in the $1.5-3.5$ TeV range, where resonant searches may have less reach. This enhancement is just at the projected 2$\sigma$ sensitivity of the HL-LHC. We find there are resonance masses for which the change in the Higgs trilinear is maximized while the resonant rate is negligible. We provide an analytical understanding of these effects with a discussion on the interplay of various constraints on the parameter space and the Higgs trilinear coupling.

    hep-phPRD(2025)·12 citations
14. 14*

    Rotation induced color confinement

    Guojun Huang🇨🇳 · Shile Chen🇨🇳 · Yin Jiang🇨🇳 · Jiaxing Zhao🇩🇪 · Pengfei Zhuang🇨🇳

    The rotation effect on the QCD properties is an open question. We study the dynamic gluon mass in a dense QCD matter, the rotation is introduced by taking a covariant transformation between the flat and curved spaces. The law of causality which restricts the rotation strength of the system is carefully considered in the calculation. we find that the rotation effect is not monotonous. Overall, it behaves like an anti-screening effect, reflecting in the decreasing gluon mass, but the strength changes with the rotation. For a QCD matter with low baryon density, the screening effect in the flat space can be completely canceled by the rotation, and gluons are confined in a strongly rotating matter. When the rotation is extremely high, the matter approaches to a weakly interacting gas.

    hep-phnucl-thPLB(2025)·0 citations
15. 15*

    Investigating the Bulk Properties of Charged Particles in Different $\eta$ Bins Using a Modified Tsallis Model

    Haifa I. Alrebdi🇸🇦 · Muhammad Ajaz🇵🇰 · Murad Badshah🇵🇰 · Muhammad Waqas🇨🇳 · Nourah A.M. Alsaif🇸🇦

    This paper presents a comprehensive analysis of the double-differential $p_T$ distributions of charged particles in twelve distinct pseudorapidity regions of equal width in $pp$ collisions at center-of-mass energies of 0.9, 2.36, and 7 TeV. Utilizing the modified Tsallis function with mean transverse flow velocity, our study demonstrates a very good agreement between experimental data and the model employed. The fit quality is consistently high across all $p_T$ ranges, as assessed by Data/Fit panels accompanying each plot. Extracted parameters, including kinetic freeze-out temperature ($T_0$), transverse flow velocity (${\beta }_T$), non-extensivity parameter ($q$) and mean transverse momentum $⟨p_T⟩$ dependencies are shown on pseudorapidity ($\eta$) and collision energy ($\sqrt{s}$). $T_0$, ${\beta }_T$ and $⟨p_T⟩$ exhibit a decreasing trend with increasing $\eta$ due to lower in energy transfer along high $\eta$ regions, while they show a heightened sensitivity to $\sqrt{s}$. $q$ increases with $\eta$, indicating a closer thermal equilibrium in mid-$\eta$ particles. The paper also explores correlations among these parameters, emphasizing relationships between $T_0$, ${\beta }_T$, $q$ and $⟨p_T⟩$. Our study provides valuable insights into the thermal and dynamic characteristics of high-energy proton-proton collisions, contributing to the broader understanding of the bulk properties of nuclear matter produced in these interactions.

    hep-phnucl-th0 citations
16. 16*

    Amplitude-Based IR-Improvement in Precision LHC$/$FCC Physics

    B.F.L. Ward (1)🇺🇸 · S. Jadach (2)🇵🇱 · W. Placzek (3)🇵🇱 · M. Skrzypek (2)🇵🇱 · Z. Was (2)🇵🇱 · S.A. Yost (4) ((1) Baylor University, Waco, TX, USA, (2) Institute of Nuclear Physics, Krakow, PL, (3) Institute of Applied Computer Science, Jagiellonian University, Krakow, PL, (4) The Citadel, Charleston, SC, USA)🇺🇸

    We present recent results based on the IR-improvement of unintegrable singularities in the infrared regime via amplitude-based resummation in $QED\times QCD\subset SU(2{)}_L\times U_1\times SU(3{)}_c$. In the context of precision LHC$/$FCC physics, we focus on specific examples, such as the removal of QED contamination in PDFs evolved from data at ${Q_0}^2\sim 2{\text{GeV}}^2$ and used in the evaluating precision observables in $pp\to Z+X\to \ell \bar{\ell }+X^{\prime }$, in which we discuss new results and new issues.

    hep-phPoS(2025)·0 citations
17. 17*

    Gravitational Waves from the Hagedorn Phase

    Gonzalo Villa🇬🇧

    We illustrate the main points behind the computation of the gravitational wave spectrum originated from a phase in the early universe where the energy density is dominated by highly excited fundamental string degrees of freedom - a Hagedorn phase. This phase is described using the Boltzmann equation approach to string thermodynamics, which we illustrate via a toy model which permits analytic computations for the evolution of perturbations. This window into the out-of-equilibrium regime allows us to compute equilibration rates and conclude that, in realistic scenarios, long, open strings dominate the ensemble, source gravitational waves and provide a succesful reheating. Furthermore, we compare the results against the Standard Model prediction for a gravitational wave background of thermal origin and conclude that the string prediction is larger. This is one of the few cases in which a signal of stringy origin dominates over the field theory analogue. This work is based on arXiv:2310.11494 and arXiv:2408.13803 and is a contribution to the Proceedings of the 29th symposium on Particles, Strings and Cosmology (PASCOS 2024).

    ↳ hep-thastro-ph.COhep-ph5 citations
18. 18*

    Renormalons as Saddle Points

    Arindam Bhattacharya🇺🇸 · Jordan Cotler🇺🇸 · Aurélien Dersy🇺🇸 · Matthew D. Schwartz🇺🇸

    Instantons and renormalons play important roles at the interface between perturbative and non-perturbative quantum field theory. They are both associated with branch points in the Borel transform of asymptotic series, and as such can be detected in perturbation theory. However, while instantons are associated with non-perturbative saddle points of the path integral, renormalons have mostly been understood in terms of Feynman diagrams and operator product expansions. We suggest a non-perturbative path integral explanation of how both instantons and renormalons produce singularities in the Borel plane using representative finite-dimensional integrals. In particular, we build evidence that renormalons can be understood as saddle points of the 1-loop effective action, enabled by a crucial contribution from the quantum scale anomaly. These results are illustrated in simple toy models and indicate a possible route toward studying renormalons within realistic asymptotically-free field theories.

    ↳ hep-thhep-phJHEP(2026)·6 citations
19. 19*

    Relativistic spin hydrodynamics revisited with general rotation by entropy-current analysis

    Lixin Yang🇨🇳 · Li Yan🇨🇳

    We revisit the canonical formulation of spin hydrodynamics for Dirac fermions with a general thermal vorticity. The orders of the general thermal vorticity and the corresponding spin variables are considered independently from those of the conventional hydrodynamic variables and their perturbative gradients. Assuming a totally antisymmetric spin current of Dirac fermions, the entropy-current analysis with a general spin potential indicates that the constitutive relations of the stress-energy tensor have to involve spin variables, particularly those linked to boost symmetry, to adhere to the entropy principle. In the presence of the degree of freedom associated with boost symmetry, we choose the constitutive relations of the canonical formulation to be connected to those of the phenomenological formulation through pseudogauge transformation. Subsequently, a linear-mode analysis is conducted using the resulting spin hydrodynamic equations. It is observed that the spin and hydrodynamic modes in this canonical formulation display different characteristics compared to those in the phenomenological formulation up to the second order of gradient.

    ↳ nucl-thhep-phhep-th3 citations
20. 20*

    Light burden of memory: Constraining primordial black holes with high-energy neutrinos

    Marco Chianese🇮🇹 · Andrea Boccia🇮🇹 · Fabio Iocco🇮🇹 · Gennaro Miele🇮🇹 · Ninetta Saviano🇮🇹

    Recent studies point out that quantum effects, referred to as "memory burden", may slow down the evaporation of black holes. As a result, a population of light primordial black holes could potentially survive to the present day, thus contributing to the energy density of dark matter. In this work, we focus on light primordial black holes with masses $M_{\mathrm{PBH}}\lesssim 10^9\mathrm{g}$ that, due to the memory burden effect, are currently evaporating, emitting high-energy particles, among which neutrinos, in the local Universe. Analyzing the latest IceCube data, we place novel constraints on the combined parameter space of primordial black holes and the memory burden effect. We also study the projected reach of future neutrino telescopes such as IceCube-Gen2 and GRAND. We find that the neutrino observations are crucial to probe scenarios with highly-suppressed evaporation and light masses for primordial black holes.

    ↳ astro-ph.HEastro-ph.COhep-phPRD(2025)·50 citations
21. 21*

    Quantum Hall liquids in high-density QCD

    Kentaro Nishimura🇯🇵 · Naoki Yamamoto🇯🇵 · Ryo Yokokura🇯🇵

    There exist metastable domain walls of the flavor-singlet meson $\eta$ for the $\mathrm{U}(1)$ axial symmetry in two-flavor color superconductivity (2SC) in QCD at large baryon density. We show that, due to the coupling of $\eta$ to confined $\mathrm{SU}(2)$ gluons in the 2SC phase, the effective theory on the domain wall is described by the $\mathrm{SU}(2{)}_{-1}$ Chern-Simons theory, which is dual to the $\mathrm{U}(1{)}_2$ Chern-Simons theory. This theory has a spin-1 droplet excitation that does not carry a baryon number, which we identify as a vector meson. We also discuss the effective theories and baryonic droplet excitations on the domain walls of the flavor-singlet mesons in the superfluid phases of QCD at large isospin density and two-color QCD at large baryon density.

    ↳ hep-thcond-mat.mes-hallhep-phnucl-thPRD(2025)·0 citations
22. 22*

    Unified Origin of Curvature Perturbation and Baryon Asymmetry of the Universe

    Anish Ghoshal🇵🇱 · Abhishek Naskar🇮🇳 · Nobuchika Okada🇺🇸

    We propose a unified framework that describes both the curvaton mechanism for generating primordial density fluctuations and the Affleck-Dine (AD) mechanism for baryogenesis. By introducing a complex scalar field (AD field) carrying a baryon/lepton number and its potential consisting of quadratic and quartic terms with a small baryon/lepton-number-violating mass term, we investigate the evolution of the scalar field during the radiation-dominated era following inflation. We set the initial conditions such that the quartic term dominates the scalar potential, and the angular component of the AD field is non-zero. We focus on a scenario where the AD field sufficiently dominates the energy density of the universe before its decay. We show that the radial component of the AD field can be identified with the curvaton to solely produce the Planck normalized scalar power spectrum while the evolution of the angular component is crucial for generating the observed baryon asymmetry of the universe. Additionally, we find that the amplitude of scalar bispectrum $f_{NL}$ is negative, which is consistent with the current Planck data and testable in future observations such as CMB-S4, LiteBIRD, LSS, and 21-cm experiments. In our estimation of the scalar power spectrum and bispectrum, we develop a novel analytical scheme for computing scalar fluctuations based on the $\delta N$ formalism, which allows us to deal with the evolution of curvaton with polynomial potential more accurately in comparison to the existing analytical methods.

    ↳ astro-ph.COhep-phJHEP(2026)·3 citations
23. 23*

    Asymptotic Safety and the Cosmic Coincidence Problem

    Vasilios Zarikas

    Asymptotic Safety (AS) Paradigm is an interesting set of ideas and methods towards a meaningful quantization of Gravity. A brief review of phenomenological consequences in the context of AS regarding cosmology with emphasis on dark energy is given. Furthermore, recent studies that suggest a natural explanation of the recent cosmic acceleration and its coincidence using large-scale structure and AS framework will be analyzed. Finally, the present work extends the analysis of a recent new set of modified Einstein equations inspired from AS program.

    ↳ gr-qcastro-ph.COhep-phhep-thPoS CORFU2022 (2023) 203
24. 24*

    Multimessenger signatures of a deformed magnetar in gamma-ray bursts

    Parisa Hashemi · Soroush Shakeri🇮🇷 · Yu Wang🇨🇳 · Liang Li · Rahim Moradi🇨🇳

    We study the evolution of a newly formed magnetized neutron-star (NS) as a power source of gamma-ray bursts (GRBs) in the light of both gravitational-wave (GW) and electromagnetic (EM) radiations. The compressible and incompressible fluids are employed in order to model the secular evolution of stable Maclaurian spheroids. It is shown that the GW and EM emissions evolve as a function of eccentricity and rotational frequency with time. We find that the luminosity characteristics crucially depend on NS parameters such as magnitude and structure of magnetic field, ellipticity and the equation of state (EoS) of the fluid. The presence of X-ray flares, whose origins are not yet well understood, can be captured in our model regarding some specific nuclear EoSs. Our model allowing us to explain flares that occur within the wide range of $10$ to $10^4$ s and the peak EM luminosity in the order of $10^{46}$ - $10^{51}$ $\text{erg}{\mathrm{s}}^{-1}$ by using a reasonable set of parameters, such as magnetic field strength around $10^{14}-10^{16}$ G, the quadrupole-to-dipole ratio of magnetic field up to 500. By applying our model to a sample of GRB X-ray flares observed by the Swift/X-ray Telescope, we try to constraint the crucial parameters of a deformed magnetar via a Marcov Chain Monte Carlo fitting method. Our analysis shows that ongoing and upcoming joint multimessenger detections can be used to understand the nature of a GRB's central engine and its evolution at the early times of the burst formation.

    ↳ astro-ph.HEastro-ph.COhep-phApJ(2025)·4 citations
25. 25*

    Does Gauss-Bonnet Inflationary Gravitational Waves satisfy the Pulsar Timing Arrays observations?

    Lu Yin🇨🇳

    The observations from pulsar timing arrays (PTAs), led by the North American Nanohertz Observatory for Gravitational Waves (NANOGrav), have provided opportunities to constrain primordial gravitational waves at low frequencies. In this paper, we analyze the best-fit parameter values for different Gauss-Bonnet Inflationary Gravitational Wave (GB-IGW) models with the PTArcade program, and we compare the results with the observations of NANOGrav, European Pulsar Timing Array (EPTA), Parkes Pulsar Timing Array (PPTA), and International Pulsar Timing Array (IPTA). We find the potential parameter $n$ derived from the GB-IGW model is not necessarily positive. Instead, PTA data suggest the possibility of new parameter ranges. Meanwhile, the other parameters' results, such as the spectral indices of the scalar and tensor perturbation also have differences with traditional Cosmic Microwave Background analyses from Planck 2018, showing the reason for the different phenomena of Gravitational Wave power spectra expected. Additionally, the GB-IGW models we calculated are closer to the central values of multiple PTA datasets compared to the standard inflation model, making the GB-IGW model more likely to be detected by future space-based gravitational wave observatories.

    ↳ astro-ph.COastro-ph.HEgr-qchep-phJCAP(2025)·3 citations
26. 26*

    Origin of hadron spin based on Lattice QCD study on the charmed hadrons

    Fangcheng He🇺🇸 · Jian Liang🇨🇳 · Yi-Bo Yang🇨🇳

    We perform the first Lattice calculation about the charmed hadron spin decomposition using overlap fermions on a 2+1 flavor RBC/UKQCD domain-wall gauge configurations at 0.083 fm with 300 MeV pion mass. It is found that the contributions of quark spin to the spin of 1S, 1P charmonia and also proton-like triple heavy quark state are comparable with the expectation of non-relativistic quark model. Such an observation provides evidence that the non-triviality of proton spin decomposition mainly arises from the relativistic effects of the light quark. Conversely, the substantial gluon angular momentum contribution in the spin $(1/2{)}^{+}$ state with triple heavy quarks at the charm quark mass, remains significant, highlighting the ongoing importance of the gluon in the realm of charmed baryon physics.

    ↳ hep-lathep-ph2 citations
27. 27*

    A universal speed limit for spreading of coherence

    Gevorg Martirosyan · Martin Gazo · Jiří Etrych · Simon M. Fischer🇩🇪 · Sebastian J. Morris · Christopher J. Ho · Christoph Eigen · Zoran Hadzibabic🇬🇧

    Discoveries of fundamental limits for the rates of physical processes, from the speed of light to the Lieb-Robinson bound for information propagation, often lead to breakthroughs in the our understanding of the underlying physics. Here we observe such a limit for a paradigmatic many-body phenomenon, the spreading of coherence during formation of a weakly interacting Bose-Einstein condensate. We study condensate formation in an isolated homogeneous atomic gas that is initially far from equilibrium, in an incoherent low-energy state, and condenses as it relaxes towards equilibrium. Tuning the inter-atomic interactions that drive condensation, we show that the spreading of coherence through the system is initially slower for weaker interactions, and faster for stronger ones, but always eventually reaches the same limit, where the square of the coherence length grows at a universal rate given by the ratio of Planck's constant and the particle mass, or equivalently by the quantum of velocity circulation associated with a quantum vortex. These observations are robust to changes in the initial state, the gas density, and the system size. Our results provide benchmarks for theories of universality far from equilibrium, are relevant for quantum technologies that rely on large-scale coherence, and invite similar measurements in other systems.

    ↳ cond-mat.quant-gascond-mat.stat-mechhep-phphysics.atom-ph+1Nature(2025)·19 citations
28. 28*

    Rapid Methods for Modeling Overdensities of Massive Neutrinos and Other Non-Cold Relics

    Keduse Worku🇺🇸 · Nashwan Sabti🇺🇸 · Marc Kamionkowski🇺🇸

    Recent work has highlighted the potentially detectable gravitational-lensing effect of neutrino halos on cosmic-microwave-background (CMB) fluctuations with upcoming instruments like SO, CMB-S4, and CMB-HD. Accurate modeling of neutrino-halo density profiles are essential for making theory predictions of their cosmological effects. Yet, they are computationally intensive, particularly in the nonlinear regime. In this work, we present an efficient numerical framework for computing neutrino profiles based on N-1-body simulations within a flat FRW Universe. Our approach enables highly parallelized, rapid calculations of neutrino trajectories near spherically symmetric dark-matter halos, delivering results within seconds. In addition to neutrinos, we demonstrate an application to model the clustering of other non-cold relics, such as a freeze-in dark-matter component. The framework is flexible in its definitions of cosmological and dark-matter-halo parameters, which can be particularly valuable for rapid-scanning tasks. It can also seamlessly incorporate new physics, as we demonstrate with examples of a time-varying gravitational constant and nonstandard neutrino phase-space distributions.

    ↳ astro-ph.COhep-phPRD(2025)·7 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.