Through the holographic correspondence, we compute the entanglement entropy of the gluonic field sourced by a quark-antiquark pair undergoing uniform back-to-back acceleration. Previous calculations had obtained this only for the case where the entanglement surface is located midway between the quark and antiquark. Here, we consider the more general case with a relative lateral displacement, and determine the entanglement entropy as a function of the distance between the quark and the entanglement surface. This setup is of interest because it departs from the usual simplifying conditions of staticity and thermality, and because it yields more information about the entanglement pattern in the gluonic field and about the possibility of eventually developing a purely worldsheet interpretation for said entanglement.

Mexico

Andrés Argandoña

Alberto Güijosa

Position dependence of the holographic entanglement entropy for an accelerating quark-antiquark pair

In this paper, we employ the gauge-gravity duality to study jet quenching (JQ) phenomena in the quark-gluon plasma. For this purpose, we implement holographic quantum chromodynamics (QCD) models constructed from an Einstein-Maxwell-dilaton gravity at finite temperature and finite chemical potential for light and heavy quarks. The models capture both the confinement and deconfinement phases of QCD and the first-order phase transitions. We calculate the JQ parameter in different models and compare them with the experimental data obtained in heavy-ions studies. In particular, we investigate how JQ, as a function of temperature <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>T</mi></math>, chemical potential <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>μ</mi></math>, and magnetic field <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>c</mi><mi>B</mi></msub></math>, serves as a probe for identifying first-order phase transitions within the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo stretchy="false">(</mo><mi>T</mi><mo>,</mo><mi>μ</mi><mo>,</mo><msub><mi>c</mi><mi>B</mi></msub><mo stretchy="false">)</mo></math> parameter space of holographic QCD. Particular attention is paid to the dependence of JQ on the parameter <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>ν</mi></math>, which characterizes longitudinal versus transverse anisotropy relative to the heavy-ion collision axis. By analyzing the dependence of the JQ parameters on these thermodynamic variables, we map critical regions associated with phase boundaries. We compare our findings to earlier studies of the running coupling constant’s behavior within the gauge-gravity duality framework. This approach provides new insights into the interplay between nonperturbative dynamics and phase structure in strongly coupled systems.

Russia

Irina Ya. Aref’eva

Ali Hajilou

Alexander Nikolaev

Pavel Slepov

Jet quenching in holographic QCD as an indicator of phase transitions in anisotropic regimes

Within the framework of an equivparticle model employing mean-field approximation, we investigate systematically the mass spectra of color-singlet <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>N</mi></math>-quark configurations with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>N</mi><mo>=</mo><mn>3</mn></math>, 6, 9, 12, 15, and 18, which are assumed to be spherically symmetric with quarks occupying the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>1</mn><msub><mrow><mi mathvariant="normal">s</mi></mrow><mrow><mn>1</mn><mo>/</mo><mn>2</mn></mrow></msub></mrow></math> state, i.e., compact multibaryon states. At a given quark number <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>N</mi></math>, these states collectively form a single irreducible representation under SU(6) symmetry. Our analysis yields comprehensive mass formulas that characterize these SU(6) multiplets, providing a unified description of their mass spectra. In order to effectively constrain the parameter space of the model and improve the prediction accuracy, we carry out a Bayesian parameter inference based on the experimental masses of eight baryons and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>D</mi><mn>03</mn></msub></math>. The posterior probability density functions and their correlations of the model parameters are examined, based on which we further predict the masses of various multibaryon states and provide their 68% and 90% credible intervals. In our prediction, H-dibaryon, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>D</mi><mn>03</mn></msub></math>, and the dibaryon with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>S</mi><mo>=</mo><mo>−</mo><mn>6</mn></math> are all bound states relative to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Λ</mi><mi mathvariant="normal">Λ</mi></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Δ</mi><mi mathvariant="normal">Δ</mi></math>, and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Ω</mi><mi mathvariant="normal">Ω</mi></math> thresholds, while slight probabilities of other stable dibaryons (23.64% more stable than <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi mathvariant="normal">Ω</mi><mo>−</mo></msup><msup><mi mathvariant="normal">Ξ</mi><mn>0</mn></msup></math> for the state with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>I</mi><mo>=</mo><mfrac><mn>1</mn><mn>2</mn></mfrac></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>S</mi><mo>=</mo><mo>−</mo><mn>5</mn></math> and 92.49% more stable than <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi mathvariant="normal">Ξ</mi><mn>0</mn></msup><msup><mi mathvariant="normal">Ξ</mi><mo>−</mo></msup></math> for the state wtih <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>I</mi><mo>=</mo><mn>0</mn></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>S</mi><mo>=</mo><mo>−</mo><mn>4</mn></math>) and tribaryons (0.25% more stable than <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi mathvariant="normal">Ξ</mi><mo>−</mo></msup><msup><mi mathvariant="normal">Ξ</mi><mn>0</mn></msup><msup><mi mathvariant="normal">Ξ</mi><mn>0</mn></msup></math> for the state wtih <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>S</mi><mo>=</mo><mo>−</mo><mn>6</mn></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>I</mi><mo>=</mo><mn>1</mn><mo>/</mo><mn>2</mn></math>; 2.19% more stable than <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Λ</mi><msup><mi mathvariant="normal">Ξ</mi><mn>0</mn></msup><msup><mi mathvariant="normal">Ξ</mi><mo>−</mo></msup></math> for the state with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>S</mi><mo>=</mo><mo>−</mo><mn>5</mn></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>I</mi><mo>=</mo><mn>0</mn></math>; and 2.21% more stable than <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Λ</mi><mi mathvariant="normal">Λ</mi><msup><mi mathvariant="normal">Ξ</mi><mn>0</mn></msup></math> for the state with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>S</mi><mo>=</mo><mo>−</mo><mn>4</mn></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>I</mi><mo>=</mo><mn>1</mn><mo>/</mo><mn>2</mn></math>) are observed as well. For heavier compact multibaryon states, it is unlikely for them to be stable. The stable and unstable multibaryon states examined in this work may persist in compact stars, which could be helpful for us to understand the essence of pulsarlike objects.

China

Hao-Song You

Xinmei Zhu

Cheng-Jun Xia

Jialun Ping

Ren-Xin Xu

Multibaryon states in the framework of an equivparticle model

Motivated by the work of Longhi and Materassi, who constructed a realization of the (centerless) <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>BMS</mi></mrow><mrow><mn>4</mn></mrow></msub></mrow></math> algebra for the massive Klein-Gordon field in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>3</mn><mo>+</mo><mn>1</mn></math> dimensions, we build a realization of the (centerless) massless <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>BMS</mi></mrow><mrow><mn>4</mn></mrow></msub></mrow></math> algebra including superrotations. This realization depends only on the momenta in the light cone expressed in celestial coordinates without any reference to the Klein-Gordon field. The quadratic Casimir of the Lorentz algebra is written in terms of a second order differential operator and the volume form plays an essential role in this construction. The <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>BMS</mi></mrow><mrow><mn>4</mn></mrow></msub></mrow></math> algebra in terms of vector fields shows its kinematical nature, like the Poincaré algebra. We also construct a dynamical realization of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>BMS</mi></mrow><mrow><mn>4</mn></mrow></msub></mrow></math> from the symplectic structure on the solutions of the massless four-dimensional Klein-Gordon field in terms of quadratic expressions of the Fourier modes and plane waves invariant under translations. Using the Mellin transform, we rewrite the Klein-Gordon field in terms of the boost invariant basis, and write down the corresponding <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>BMS</mi></mrow><mrow><mn>4</mn></mrow></msub></mrow></math> realization. We also provide the relation with spherical harmonics, linking our results with the solutions of Longhi-Materassi, which are in fact a subset of ours.

Spain

Carles Batlle

Italy

Roberto Casalbuoni

Daniele Dominici

United Kingdom

José Figueroa-O’Farrill

Joaquim Gomis

Celestial kinematical interpretation for an extended <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>BMS</mi></mrow><mrow><mn>4</mn></mrow></msub></mrow></math> algebra

Quantum field theory in the presence of localized solitons is more complicated than vacuum sector quantum field theory, largely as a result of the soliton’s zero modes. In the present work, we try to understand to what extent this situation carries over to extended solitons. To this end, we explicitly construct the quantum state corresponding to a domain wall string or membrane, treating the zero modes carefully. This is done both for compact and also infinitely extended solitons. As an application, we calculate the differential probability for a domain wall string’s translation mode, with a given momentum, to be excited by a single quantum of incoming radiation.

Jarah Evslin

Armenia

Hui Liu

An extended Soliton’s zero modes

We analyse electromagnetic leptogenesis within the framework of an effective field theory, where the dynamics is governed by the gauge-invariant dipole operator $${\mathcal{O}}_{NB}=\left(\overline{L}{\sigma }^{\mu \nu }N\right)\widetilde{H}{B}_{\mu \nu }$$ . The Wilson coefficient $\textit{C}$ is matched at one loop and evolved to the electroweak scale via renormalisation-group (RG) running. After electroweak symmetry breaking, we compute flavour-dependent decay widths and CP asymmetries for the two-body modes $\textit{N}$ → $\textit{νγ}$ and $\textit{N}$ → $\textit{νZ}$, and solve the fully flavoured Boltzmann equations. In the $\textit{N}$ -dominated regime, the freeze-out baryon asymmetry is $${Y}_{B}^{\text{FO}}\lesssim {1}{0}^{-{17}}$$ , far below the observed value $${Y}_{B}^{\text{obs}}\simeq 8.7\times {10}^{-11}$$ . The suppression is structural: gauge invariance forces a Higgs insertion; therefore the dipole coupling scales as $$\mu \propto v/{M}_{\psi}^{2}$$ , while the matched Wilson coefficient $\textit{C}$ is loop-generated and further suppressed by RG running. We note that in the quasi-degenerate limit the self-energy resonance can be operative and suggest a plausible path to $${Y}_{B}^{\text{obs}}$$ .

Japan

Rin Takada

Electromagnetic leptogenesis — an EFT-consistent analysis via Wilson coefficients. Part I. Low-scale, non-resonant regime

This paper investigates the normal modes of a probe scalar field in a five-dimensional AdS-Schwarzschild black hole with the brick wall boundary condition near the horizon. We employ various techniques to compute the spectrum and analyze its properties. Our results reveal a linear dependence of the spectrum on the principal quantum number while demonstrating a nontrivial dependence on the angular momentum quantum number. We compute the spectral form factor (SFF) and find a dip-ramp-plateau structure, with the slope of the ramp approaching unity as the brick wall nears the horizon. This feature appears to vanish when the horizon size becomes much larger compared to the anti–de Sitter length. We also observe that as the brick wall approaches the horizon, the poles of the retarded Green’s function condense on the real line, leading to an emergent thermal behavior in the boundary theory. This work extends previous studies on lower-dimensional black holes to higher dimensions, providing insights into the connection between black hole microstate models and boundary chaos. Our findings contribute to the ongoing discussions on the information paradox and the nature of black hole interiors in the context of anti–de Sitter/conformal field theory correspondence.

India

Suman Das

Somnath Porey

Baishali Roy

Brick wall in an AdS-Schwarzschild black hole: Normal modes and emerging thermality

In this article, we investigate the orbital dynamics and quasi-periodic oscillations (QPOs) surrounding a static, spherically symmetric geometry of an Einstein–nonlinear Maxwell–-Yukawa (ENLMY) black hole (BH). Using the Hamiltonian formalism, we derive equations of motion and analyze the effective potential. We determine the innermost stable circular orbit (ISCO) and innermost bound circular orbit (IBCO) radii for different values of the Yukawa parameters $$\lambda $$ and $$\delta $$ , and classify periodic orbits via rational frequency analysis, highlighting deviations from Schwarzschild geometry. We also study gravitational wave (GW) emission from periodic orbits and show how Yukawa terms affect GW signals. Fundamental frequencies are computed, and QPOs are analyzed using relativistic precession, warped disk, and tidal disruption models. By increasing $$\lambda $$ , the ENLMY spacetime effectively mimics the behavior of a Schwarzschild spacetime. Constraints on the BH mass and Yukawa parameters are derived using QPO data from stellar-mass (XTE J1550-564, GRO J1655-40, GRS 1915+105), intermediate-mass (M82 X-1), and supermassive (SgrA*) BHs within the relativistic precession model by employing a Markov chain Monte Carlo analysis.

Pakistan

Tehreem Zahra

Oreeda Shabbir

Bushra Majeed

Azerbaijan

Mubasher Jamil

Uzbekistan

Javlon Rayimbaev

Abubakir Shermatov

Gravitational wave radiation from periodic orbits and quasi-periodic oscillations in an Einstein nonlinear Maxwell–Yukawa black hole

The Sakai-Sugimoto holographic model is famous for implementing the approximate chiral symmetry of QCD and reproducing the Chiral Lagrangian in a top-down approach. In this manuscript, we revisit the model in a formalism that is somewhat different from the original work by Sakai and Sugimoto: we start by identifying boundary degrees of freedom and splitting the bulk equations of motion into dynamical ones and constraints. The former are then solved to all orders in derivatives of the boundary fields. The constraints are left unsolved, leaving the dynamical degrees of freedom off-shell. This approach enables us to systematically derive the effective action of the boundary theory. The derived effective action is very rich in physics: it contains an U($\textit{N}$ ) multiplet of massless pseudoscalars interacting (via trilinear and higher terms) with towers of massive (axial-)vector mesons. In contrast to the previous studies, our effective action is non-local. The original Chiral Lagrangian is recovered as its local expansion in small $\textit{π}$-meson momenta (derivative expansion). We particularly zoom in on the values of four derivative terms couplings, the low energy constants, and compare those with the ones reported in the literature.

Israel

Michael Lublinsky

Timofey Solomko

Sakai-Sugimoto model in an off-shell: Chiral Lagrangian to all orders

The global symmetries in maximally supersymmetric theories of gravity in <italic>d</italic>&#8239;&#8805;&#8239;4 are shown to have a universal form in light-cone superspace. The procedure for deriving an all order expression for the <math altimg='si1.svg'><mrow><mi>d</mi><mo linebreak='goodbreak'>=</mo><mn>4</mn></mrow></math> case is also discussed.

Sudarshan Ananth

Nipun Bhave

An ‘exceptional’ form for symmetries in maximal supergravity