This research work investigates the holographic dark energy cosmological model in the n-dimensional Kaluza–Klein space-time in the scalar–tensor theory of gravitation proposed by Brans–Dicke. A deterministic solution of the field equations is obtained and physical and kinematical properties of the obtained model are analysed through graphical representation. The density parameters of the dark matter and holographic dark energy are examined in detail. Also, the stability of cosmological model is ensured by using perturbation of metric. Furthermore, the diagnostic tools such as jerk parameter, statefinder pair, energy conditions and $$\omega _{\lambda } -{\omega }'_{\lambda }$$ plane are also studied to study the cosmological evolution.

India

S. Wankhade

A. Nimkar

Stability of n-dimensional Kaluza–Klein cosmological model in scalar–tensor theory of gravitation proposed by Brans–Dicke

The manifest disparity in Hawking radiation temperatures between black hole and cosmological horizons in de Sitter (dS) spacetime reveals a non-equilibrium thermal configuration, inherently violating thermodynamic stability criteria. This asymmetry poses significant challenges to the systematic analysis of dS thermodynamics. In this study, we construct a thermodynamic framework for dS spacetime under the condition that the system’s thermodynamic quantities adhere to the first law of thermodynamics, while enforcing thermal equilibrium between horizons through radiation temperature-equivalent conditions. Our ansatz postulates that spacetime entropy constitutes both horizon entropy contributions with a supplementary correction term. Through variational analysis constrained by equilibrium thermodynamics, we derive and solve thermodynamic constraints to obtain corrected entropy relations that explicitly resolve the two-horizon entropy puzzle for $\textit{n}$-dimensional charged dilaton-dS black holes. Utilizing these corrected entropy relations, we renormalize associated thermodynamic quantities, thereby establishing self-consistent extended thermodynamics. Numerical solutions of the Gibbs criteria reveal parameter-dependent critical points, where heat capacity is diverging signal possible second-order phase transitions. The system manifests phase transition phenomena, structurally homologous to liquid–gas transition in conventional thermodynamic systems. We proved that the system satisfies the conditions for equilibrium stability, allowing equilibrium phase transitions to occur near critical points.

China

Hui-Hua Zhao

Yun-Zhi Du

Yu-Bo Ma

Entropy correction and phase transition of $\textit{n}$-dimensional charged dilaton dS black holes

The energy dependence of the cross section of the ( <italic>n,p</italic>) and ( <italic>n,d</italic>) reactions on natC has been studied for the first time at the n_TOF facility at CERN, from the particle detection threshold up to 25 MeV. The measurement was performed with two telescopes made of position-sensitive silicon &#916; <italic>E</italic>- <italic>E</italic> detectors, covering the angular range from 20 &#8728; to 140 &#8728;. A detector efficiency has been determined by means of Monte Carlo simulations of the experimental setup. Various assumptions on the angular distributions and branching ratios of the excited levels of the residual 11B, 12B, 13B nuclei were considered. In particular, theoretical calculations based on the TALYS-2.0 code were used and the systematic uncertainties in the analysis results were determined from the variations in these distributions. The n_TOF data on the ( <italic>n,p</italic>) and ( <italic>n,d</italic>) reaction on carbon are characterized by a higher accuracy and wider energy range than currently available in literature. A comparison with current evaluations from different libraries reveals a rather significant disagreement with the n_TOF results, while a remarkable agreement is observed with the prediction of TALYS-2.0 for this light element.

Croatia

P. Žugec

Italy

N. Colonna

Switzerland

D. Rochman

M. Barbagallo

Poland

J. Andrzejewski

J. Perkowski

A. Ventura

D. Bosnar

A. Gawlik-Ramięga

Spain

M. Sabaté-Gilarte

Austria

France

M. Bacak

F. Mingrone

United Kingdom

E. Chiaveri

O. Aberle

V. Alcayne

S. Amaducci

L. Audouin

V. Babiano-Suarez

S. Bennett

E. Berthoumieux

J. Billowes

A. Brown

M. Busso

M. Caamaño

L. Caballero-Ontanaya

F. Calviño

M. Calviani

D. Cano-Ott

A. Casanovas

F. Cerutti

G. Cortés

M.A. Cortés-Giraldo

L. Cosentino

S. Cristallo

L.A. Damone

P.J. Davies

Greece

M. Diakaki

M. Dietz

C. Domingo-Pardo

R. Dressler

Germany

Q. Ducasse

E. Dupont

I. Durán

Z. Eleme

B. Fernández-Domínguez

A. Ferrari

P. Finocchiaro

V. Furman

K. Göbel

R. Garg

S. Gilardoni

Portugal

I.F. Gonçalves

E. González-Romero

C. Guerrero

F. Gunsing

Japan

H. Harada

S. Heinitz

Belgium

J. Heyse

D.G. Jenkins

A. Junghans

F. Käppeler

Y. Kadi

A. Kimura

Czechia

I. Knapová

M. Kokkoris

Y. Kopatch

M. Krtička

D. Kurtulgil

I. Ladarescu

C. Lederer-Woods

H. Leeb

J. Lerendegui-Marco

S.J. Lonsdale

D. Macina

A. Manna

T. Martínez

M. Martínez-Cañada

A. Masi

C. Massimi

P. Mastinu

M. Mastromarco

E.A. Maugeri

A. Mazzone

E. Mendoza

A. Mengoni

V. Michalopoulou

P.M. Milazzo

J. Moreno-Soto

A. Musumarra

Romania

A. Negret

R. Nolte

F. Ogállar

A. Oprea

N. Patronis

A. Pavlik

C. Petrone

L. Piersanti

E. Pirovano

I. Porras

J. Praena

Measurement of the natC( <italic>n,p</italic>) and natC( <italic>n,d</italic>) reactions from n_TOF at CERN

We study the sphere partition function of 3d $$ \mathcal{N} $$ = 2 holographic SCFTs arising on the worldvolume of $\textit{N}$ coincident M2-branes in the presence of squashing and real mass deformations. We argue that the all-order large $\textit{N}$ perturbative expansion of the partition function resums into a compact expression in terms of an Airy function. We provide ample evidence for this conjecture using numerical methods, saddle point analysis in the ’t Hooft limit, and the relation of the squashed sphere partition function to the Cardy-like limit of the superconformal index. We also discuss the relation of our results to topological string theory and the statistical mechanics of Fermi gases. Our conjecture has a bearing on the AdS/CFT correspondence and the structure of perturbative M-theory corrections to 11d supergravity which we discuss.

Nikolay Bobev

Pieter-Jan Smet

South Korea

Junho Hong

Valentin Reys

Xuao Zhang

An Airy tale at large $\textit{N}$

We study $$ \frac{1}{4} $$ -BPS Wilson loops in four-dimensional SU($\textit{N}$) $$ \mathcal{N} $$ = 2 super-Yang-Mills theories with conformal matter in an arbitrary representation $$ \mathcal{R} $$ . These operators are formed of two meridians on the two-sphere separated by an arbitrary opening angle. We conjecture that these observables are encoded in a modification of Pestun’s matrix model. The matrix representation of these operators resembles that of the $$ \frac{1}{2} $$ -BPS circular Wilson loop, differing only for a rescaling in the exponent. We compare the matrix model predictions with an explicit three-loop calculation in flat space based on standard Feynman-diagram techniques, finding perfect agreement. Finally, exploiting the matrix model representation of these Wilson loops, we study the large-$\textit{N}$ limit at strong coupling of $$ \mathcal{N} $$ = 2 superconformal QCD, finding a surprising transition in the vacuum expectation value for a critical opening angle.

L. Griguolo

L. Guerrini

A. Testa

Into the wedge of $$ \mathcal{N} $$ = 2 superconformal gauge theories

We introduce a new approach to modeling transition distribution amplitudes (TDAs) for the processes <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>e</mi><mi>p</mi><mo stretchy="false">→</mo><mi>e</mi><mi>n</mi><msup><mi>π</mi><mo>+</mo></msup></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>e</mi><mi>p</mi><mo stretchy="false">→</mo><mi>e</mi><mi>p</mi><msup><mi>π</mi><mn>0</mn></msup></math>. The modeling is flexible, constrained by sparsely available experimental data, and satisfies theoretical requirements, including reduction to nucleon distribution amplitudes in the appropriate limit. We study the sensitivity of observable predictions to various modeling assumptions. We discuss unpolarized cross sections, as well as the three nonvanishing polarization observables at leading twist, namely, the single transverse target spin asymmetry and the two double spin asymmetries that occur with a polarized lepton beam on either a longitudinally or transversely polarized target. The analysis is complemented by a simple Monte Carlo study to provide guidance for exploring exclusive processes in the so-called backward kinematics. Our work aims to highlight the importance of future measurements to better constrain TDAs and to support upcoming experimental proposals.

B. Pire

Russia

K. Semenov-Tian-Shansky

P. Sznajder

L. Szymanowski

Toward an advanced phenomenology of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>π</mi><mi>N</mi></math> transition distribution amplitudes

It has been known for some time that generalised geometry provides a particularly elegant rewriting of the action and symmetries of 10-dimensional supergravity theories, up to the lowest nontrivial order in fermions. By exhibiting the full symmetry calculations in the second-order formalism, we show in the $$ \mathcal{N} $$ = 1 case that this analysis can be upgraded to all orders in fermions and we obtain a strikingly simple form of the action as well as of the supersymmetry transformations, featuring overall only five higher-fermionic terms. Surprisingly, even after expressing the action in terms of classical (non-generalised geometric) variables one obtains a simplification of the usual formulae. This in particular confirms that generalised geometry provides the natural set of variables for studying (the massless level of) string theory. We also show how this new reformulation implies the compatibility of the Poisson-Lie T-duality with the equations of motion of the full supergravity theory.

Julian Kupka

Charles Strickland-Constable

Fridrich Valach

Direct derivation of $$ \mathcal{N} $$ = 1 supergravity in ten dimensions to all orders in fermions

The quest to discover new 3D CFTs has been intriguing for physicists. For this purpose, fuzzy sphere regularization that studies interacting quantum systems defined on the lowest Landau level on a sphere has emerged as a powerful tool. In this Letter, we discover a series of new CFTs with global symmetry <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>Sp</mi><mo stretchy="false">(</mo><mi>N</mi><mo stretchy="false">)</mo></math> in the fuzzy sphere models that are closely related to the SO(5) deconfined phase transition, and are related to a <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>Sp</mi><mo stretchy="false">(</mo><mi>N</mi><mo stretchy="false">)</mo><mo>/</mo><mo stretchy="false">[</mo><mi>Sp</mi><mo stretchy="false">(</mo><mi>M</mi><mo stretchy="false">)</mo><mo>×</mo><mi>Sp</mi><mo stretchy="false">(</mo><mi>N</mi><mo>−</mo><mi>M</mi><mo stretchy="false">)</mo><mo stretchy="false">]</mo></mrow></math> nonlinear sigma model with a Wess-Zumino-Witten term. We numerically verify the emergent conformal symmetry by observing the integer-spaced conformal multiplets, the quality of conformal generators, and studying the finite-size scaling of the conformality. We discuss possible candidates for these newly discovered CFTs, the most plausible ones being Chern-Simons-matter theories which have <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>N</mi></math> flavors of gapless bosons or fermions coupled to a non-Abelian [viz. Sp(1), Sp(2), etc.] Chern-Simons gauge field. Our Letter provides new avenues for studying interacting CFTs in 3D, possibly facilitating the nonperturbative study of critical gauge theories and previously undiscovered CFTs.

Canada

Zheng Zhou

Yin-Chen He

3D Conformal Field Theories with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>Sp</mi><mo stretchy="false">(</mo><mi>N</mi><mo stretchy="false">)</mo></mrow></math> Global Symmetry on a Fuzzy Sphere

We derive a formula for the half-BPS interface entropy between any pair of $$ \mathcal{N} $$ = (4, 4) theories on the same conformal manifold. This generalizes the diastasis formula derived in [1] for $$ \mathcal{N} $$ = (2, 2) theories, which is restricted to the conformal submanifolds generated by either chiral or twisted chiral multiples of $$ \mathcal{N} $$ = (2, 2) supersymmetry. To derive the $$ \mathcal{N} $$ = (4, 4) formula, we use the fact that the conformal manifold of $$ \mathcal{N} $$ = (4, 4) theories is symmetric and quaternionic-Kähler and that its isotropy group contains the SU(2) ⊗ SU(2) external automorphism of the $$ \mathcal{N} $$ = (4, 4) superconformal algebra. As an application of the formula, we prove a supersymmetric non-renormalization theorem, which explains the observation in [2] that the interface entropy for half-BPS Janus solutions in type IIB supergravity on $\textit{AdS}$ × $\textit{S}$ × $\textit{T}$ coincides with the corresponding quantity in their free conformal field limits.

United States

Andreas Karch

Hirosi Ooguri

Mianqi Wang

Nonrenormalization theorem for $$ \mathcal{N} $$ = (4, 4) interface entropy

The perturbation series for the renormalization group functions of the $\textit{O}$($\textit{N}$)-symmetric $$\phi ^4$$ field theory are divergent but asymptotic. They are usually followed by Resummation calculations to extract reliable results. Although the same features exist for QED series, their partial sums can return accurate results because the perturbation parameter is small. In this work, however, we show that, for $$N\ge 4$$ , the partial sum (according to optimal truncation) of the series for the exponents $$\nu $$ and $$\eta $$ gives results that are very competitive to the recent Monte Carlo, Non-perturbative Renormalization group and Conformal field calculations. The order at which the series is truncated is inversely proportional to $$\alpha =\sigma \varepsilon =\frac{3\varepsilon }{N+8}$$ which is higher for larger $\textit{N}$ while the error is smaller. Thus as $\textit{N}$ increases one expects accurate perturbative results like the QED case. Such optimal truncation, however, doesn’t work for the series of the critical exponent $$\omega $$ (for intermediate values of $\textit{N}$) as the truncated series includes only the first order. Nevertheless, for $$N\ge 4$$ , the large-order parameter $$\sigma =\frac{3}{N+8}$$ is getting smaller which rationalizes for the use of Pad $$\acute{\textrm{e}}$$ approximation. For that aim, we first obtain the seven-loop $$\varepsilon $$ -series from the recent available corresponding $\textit{g}$-expansion. The seven-loop Pad $$\acute{\textrm{e}}$$ approximation gives accurate results for the three exponents. Besides, for all the seven orders in the series, the large-$\textit{N}$ limit leads to the exact result predicted by the non-perturbative 1/$\textit{N}$-expansion.

Qatar

Abouzeid Shalaby

Accurate critical exponents from the optimal truncation of the $$\varepsilon $$ -expansion within the $\textit{O}$($\textit{N}$)-symmetric field theory for large $\textit{N}$