This paper investigates a warm Dirac–Born–Infeld (DBI) inflationary model with nonminimal derivative coupling (NMDC) to gravity, where the inflaton kinetic term interacts with the Einstein tensor, thereby improving the effective gravitational friction. This model seamlessly integrates the noncanonical DBI kinetic structure, the NMDC-induced gravitational friction, and thermal dissipation. We formulate the background evolution equations along with the corresponding slow-roll stability conditions, leading to analytic results for the scalar spectral index $$n_s$$ and the tensor-to-scalar ratio $\textit{R}$. By applying these results to power-law potentials with $$n=2$$ and $$n=4$$ , we constrain the model parameter space using the $\textit{Planck}$ 2018 data together with BK15 and BAO measurements. The findings indicate that the interaction between NMDC-induced gravitational friction and thermal dissipation effectively modulates $$n_s$$ and significantly expands the viable parameter space. In the $$(n_s,R)$$ plane, the predictions for $$N=50$$ fall within the 95% confidence-level (CL) region, while those for $$N=60$$ extend into the 68% CL region and approach the observationally preferred central values. For the representative parameter choices examined, the tensor-to-scalar ratio is notably suppressed, generally within the range $$10^{-8}\lesssim R\lesssim 10^{-5}$$ . We also compare our results with the recent ACT DR6 observations, showing that the tighter constraints do not introduce significant observational tension for our model. Moreover, the combined damping mechanism relaxes the slow-roll condition related to $$\eta $$ and limits the inflaton field excursion, thus addressing the $$\eta $$ problem without incurring super-Planckian field variations. These results indicate that warm DBI inflation with NMDC offers a theoretically coherent and observationally viable inflationary model, showcasing the complementary effects of thermal dissipation and enhanced gravitational friction in the context of modified gravity.

China

Run-Qing Zhao

Xiao-Min Zhang

Peng-Cheng Chu

Yun-Cai Feng

Dynamics and observational signatures of warm Dirac–Born–Infeld inflation with nonminimal derivative coupling

The so-called geometric trinity of gravity is based on three distinct geometric features of spacetime, i.e. curvature, torsion and non-metricity, which give rise to equivalent dynamics for general relativity (GR), teleparallel equivalent of general relativity (TEGR) and symmetric teleparallel equivalent of general relativity (STEGR). Pre-geometric gravity, on the other hand, offers a unifying framework from which all metric-affine theories can emerge. Starting from a gauge formulation $\textit{à la}$ Yang–Mills with a Higgs-like field, a mechanism of spontaneous symmetry breaking can give rise to an effective metric as well as to the classical dynamics of the gravitational field. In particular, the emergence of gravity in the spontaneously broken phase is shown to be consistent with all the different formulations of the geometric trinity of gravity, in terms both of actions and of gauge choices for the affine connection. This general result is achieved by deriving and analysing suitable expressions in the unbroken phase for pre-geometric actions and for pre-geometric gauge-fixing conditions respectively.

Italy

Salvatore Capozziello

United States

Giuseppe Meluccio

The pre-geometric origin of geometric trinity of gravity

Semivisible jets (SVJs) provide a characteristic collider signature of strongly interacting dark sectors, in which the key model parameter <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>r</mi></mrow><mrow><mi>inv</mi></mrow></msub></mrow></math> controls the fraction of dark hadrons decaying to dark matter candidates. In this work, a regression model is developed to reconstruct <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>r</mi><mi>inv</mi></msub></math> in SVJ events produced in association with an energetic photon. The model uses information from high-level physics objects only, and the training procedure is optimized to ensure applicability. The performance is found to be robust against varying signal parameters and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>r</mi><mi>inv</mi></msub></math> can be reconstructed at a much higher precision, compared to previously developed analytical method. It offers a new approach to conduct SVJ searches that can potentially unify both <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>s</mi></math>-channel and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>t</mi></math>-channel productions, enhancing the sensitivities.

Yin Li

Jian Bin Wang

Jia Qi Xie

Kai Rong Xu

Rui Han Ye

Zi Huan Huang

Bingxuan Liu

Reconstructing the invisible fraction of semivisible jets in ISR-boosted events via neural network regression

We study a chaos-integrability transition purely within a BPS subspace, the subspace of exactly degenerate ground states annihilated by the supercharges, in a supersymmetric model that interpolates between the chaotic <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">N</mi><mo>=</mo><mn>2</mn></math> SYK model and an integrable <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">N</mi><mo>=</mo><mn>2</mn></math> “commuting” SYK model. Since all BPS states are degenerate under the Hamiltonian, conventional Hamiltonian level statistics cannot diagnose chaos within the BPS subspace. Using the framework of BPS chaos, we instead analyze the spectrum of a simple operator projected onto the BPS subspace. We numerically find that its spectral statistics exhibit random-matrix behavior near the SYK regime and undergo a smooth crossover to Poisson statistics near the integrable regime. Our results provide a direct example in which the BPS data alone diagnose the chaos-integrability crossover.

Japan

Leon Miyahara

Shono Shibuya

Chaos-integrability transition in the BPS subspace of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">N</mi><mo>=</mo><mn>2</mn></math> SYK model

Hybrid baryons, in which gluonic degrees of freedom play an explicit dynamical role, provide a key testing ground for nonperturbative quantum chromodynamics. In this work, we investigate the mass spectrum of light hybrid baryons composed of identical quarks within a phenomenological constituent framework, applied to a quark core-gluon approximation. In this approach, the hybrid baryon is described as a bound state of a color-octet three-quark core and a constituent gluon, allowing the original four-body problem to be reduced to a three-body calculation followed by an effective two-body treatment. The spectrum of the color-octet quark core is obtained by solving a semirelativistic three-quark Hamiltonian with linear confinement, Coulomb, and regularized hyperfine interactions using an oscillator basis expansion. Finite-size effects of the core are incorporated through the convolution of the effective core-gluon interaction with the spatial quark density. The resulting two-body problem, whose associated Hamiltonian has the same shape as the one of the core, is solved applying the helicity formalism and using the Lagrange mesh method. Our results predict the lightest hybrid baryons to occur at energies above 3 GeV, with negative-parity states generally lying below their positive-parity counterparts. The predicted spectra are compared with lattice QCD and QCD sum-rule calculations, showing qualitative agreement although the lowest-lying lattice QCD results are significantly lighter than the present ones. Possible extensions of the model and implications for future experimental searches are discussed.

Belgium

Joachim Viseur

Claude Semay

Cyrille Chevalier

Light hybrid baryons in the constituent model of QCD

This paper investigates the landscape of models based on modular <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>S</mi><mn>4</mn></msub></math> symmetry that predicts the trimaximal <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>TM</mi></mrow><mrow><mn>1</mn></mrow></msub></mrow></math> mixing pattern for leptonic flavor mixing, and explores their parameter spaces with constraints from the latest high-precision measurement on <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>θ</mi><mn>12</mn></msub></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Δ</mi><msubsup><mi>m</mi><mn>21</mn><mn>2</mn></msubsup></math> given by the JUNO experiment. We review how the mixing pattern arises from residual symmetries after the spontaneous breaking of a flavor symmetry, via an appropriate vacuum alignment of modular fields and flavon fields. We show three different models that realize the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>TM</mi></mrow><mrow><mn>1</mn></mrow></msub></mrow></math> in three approaches with the same symmetry structure. Due to different model building strategies used, predictions on the relations between the lightest neutrino mass and the effective Majorana mass in neutrinoless double beta decay are different, making them distinguishable.

Wen-Hao Jiang

Ruiwen Ouyang

Ye-Ling Zhou

Modular <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>TM</mi></mrow><mrow><mn>1</mn></mrow></msub></mrow></math> mixing in light of precision measurement in JUNO

We consider a general reducible gauge theory deformed by mass or/and interaction terms violating gauge invariance. It is shown that in the Abelian case, by using the Stueckelberg-type procedure, this theory with broken gauge symmetry can be converted into exactly gauge-invariant theory which under a suitable choice of gauge conditions can be treated within the formalism of minimal wave operators manageable by the covariant Schwinger-DeWitt technique. We carry out quantization of such a theory in general terms when the initial generators of gauge transformations are of the first and second stages of reducibility and derive its partition function in terms of the functional integral with all corresponding ghost fields. This method is applied to quantization of massive fermionic totally antisymmetric tensor field models in anti–de Sitter space. One-loop quantum effective action for these models is derived in the form of the functional determinants of special Dirac-type differential operators in various dimensions.

Russia

JINR

A.A. Averianov

A.O. Barvinsky

I.L. Buchbinder

V.A. Krykhtin

D.V. Nesterov

Quantization of deformed reducible gauge theories

K. Abe

M. Afif

Morocco

R. Ahl Laamara

H. Aihara

Canada

A. Ajmi

R. Akutsu

United Kingdom

H. Alarakia-Charles

I. Alekseev

Y. Alj Hakim

Switzerland

S. Alonso Monsalve

E. Amato

F. Ameli

L. Anthony

A. Araya

Brazil

A. Arguello Quiroga

S. Arimoto

Y. Asaoka

Y. Ashida

Ukraine

V. Aushev

Spain

F. Ballester Merelo

M. Barbi

G. Barr

Poland

M. Batkiewicz-Kwasniak

France

A. Beauchêne

D. Benchekroun

V. Berardi

E. Bernardini

L. Berns

S. Bhadra

N. Bhuiyan

J. Bian

D. Bianco

A. Blanchet

A. Blondel

P. Boistier

S. Bolognesi

L. Bonavera

José Bonilla

S. Bordoni

India

D. Bose

S. Boyd

C. Bozza

A. Bravar

C. Bronner

A. Bubak

A. Buchowicz

M. Buizza Avanzini

G. Burton

F. Cafagna

N. Calabria

J. Calvo Mozota

Vietnam

S. Cao

D. Carabadjac

S. Cartwright

M. Casado

M. Catanesi

C. Cavanagh

S. Cebrián

E. Chakir

S. Chakrabarty

South Korea

J. Choi

A. Choquet

Sweden

S. Choubey

Mexico

E. Chucuan Martinez

Czechia

L. Chytka

M. Cicerchia

L. Cid Barrio

M. Cieślar

J. Coleman

G. Collazuol

L. Cook

F. Cormier

D. Costas-Rodríguez

A. Craplet

S. Cuen-Rochin

C. Dalmazzone

M. Danilov

M. Daoud

T. Daret

F. Cos

E. Fuente

A. Lorenzis

G. Rosa

T. Dealtry

M. Della Valle

C. Densham

A. Dergacheva

M. Devi

F. Lodovico

A. Nitto

A. Nola

G. Díaz López

T. Dieminger

D. Divecha

M. Dobrzynska

T. Dohnal

T. Doyle

Greece

E. Drakopoulou

O. Drapier

C. Duarte Galvan

Publisher Correction: Sensitivity of the Hyper-Kamiokande experiment to neutrino oscillation parameters using accelerator neutrinos

Spacetimes with a thin shell offer a framework where both the dynamical and the thermodynamical stability of the matter comprising the shell can be consistently studied. In the present work, we consider the dynamical and the thermodynamical stability of a spherical thin shell in Einstein gravity coupled to Born-Infeld electrodynamics. For our construction, we adopt the extremally charged solution of the theory, which gives a closed analytic form for the horizon location that allows for a clear derivation of the corresponding physical quantities of interest. Under this scenario, the dynamical stability conditions under radial perturbations are readily obtained in terms of an effective potential. The equilibrium thermodynamics for such a shell is presented. We find that, despite a non-zero pressure at the shell (unlike the extremally charged Reissner–Nordström counterpart), its entropy is solely characterized as a function of the gravitational radius. We propose a physically suitable $\textit{ansatz}$ for the relevant equations of state in order to obtain a closed expression for the entropy density of the shell. We find that the thermodynamical stability conditions reduce to a single inequality related to exchanges of the charge at the shell, which determines the domain where both dynamical and thermodynamical stable configurations exist.

Argentina

Ernesto Eiroa

Griselda Figueroa-Aguirre

Bolivia

Miguel Peñafiel

Entropy and stability of an extremally charged Einstein–Born–Infeld thin shell

Scalarizations of the Einstein–Euler–Heisenberg (EEH) black hole (EEHBH) with multiple horizons are investigated in the EEH-scalar theory by introducing a quadratic scalar coupling to the Maxwell term. For mass $$M=1$$ and Euler–Heisenberg parameter $$\mu =0.03$$ , the magnetically charged EEHBH admits four horizon families (low, cold, negative, and hot), with triple horizons appearing in the narrow band of magnetic charge $$q\in [0.95,1.0065]$$ . The onset scalarization around the low, cold, and high horizons is then analyzed for the magnetic charge $$q=0.5,\,1,\,2$$ , implying infinite branches of scalarized black holes for each case. We construct the three fundamental branches of scalarized black holes. From the positivity condition of their mass, we find the upper bounds on primary scalar charges $$q_{s}$$ for scalarized low and cold horizons. These bounds determine the allowable regions for the Hawking temperature and entropy. Furthermore, we perform a time-domain stability analysis and find that the instabilities arise only at small scalar charge regime. Therefore, stable and physically viable scalarized black holes exist in an intermediate window of the primary scalar charge for low and cold horizon solutions and a lower bound for hot horizon solution.

Hong Guo

Yun Myung

Scalarization of Einstein–Euler–Heisenberg black hole with multiple horizons