The European Physical Journal C最新文献_第10页

(Lambda )CDM-like evolution in Einstein-scalar-Gauss–Bonnet gravity (Lambda )爱因斯坦-标量-高斯-邦纳引力中类似cdm的演化

IF 4.8 2区物理与天体物理

The European Physical Journal C Pub Date : 2025-09-21 DOI: 10.1140/epjc/s10052-025-14796-5

Miguel A. S. Pinto, João Luís Rosa

{"title":"(Lambda )CDM-like evolution in Einstein-scalar-Gauss–Bonnet gravity","authors":"Miguel A. S. Pinto, João Luís Rosa","doi":"10.1140/epjc/s10052-025-14796-5","DOIUrl":"10.1140/epjc/s10052-025-14796-5","url":null,"abstract":"<div><p>In this work, we analyze the Einstein-scalar-Gauss–Bonnet (EsGB) theory of gravity in a cosmological context using the formalism of dynamical systems. We obtain the equations of motion of the theory and introduce an appropriate set of dynamical variables to allow for a direct comparison with the results from General Relativity (GR). We observe that the cosmological phase space features the same set of fixed points as in standard GR, i.e., radiation-dominated, matter-dominated, curvature-dominated, and exponentially-accelerated solutions independently of the values of the coupling function and the scalar field. Furthermore, the radiation-dominated fixed points are repellers and the exponentially accelerated fixed points are attractors in the phase space, thus allowing for cosmological solutions behaving qualitatively similar to the <span>(Lambda )</span>CDM model, i.e., transitioning from a radiation-dominated phase into a matter-dominated phase, and later into a late-time cosmic acceleration phase supported by the scalar field potential. Following a reconstruction method through which we produce the cosmological solutions in the GR limit of the theory and introduce them into the general EsGB dynamical system, a numerical integration of the dynamical system shows that the EsGB theory provides cosmological solutions indistinguishable from those of the standard <span>(Lambda )</span>CDM model, compatible with the current observations from the Planck satellite and weak-field solar system dynamics, while maintaining the scalar field and the coupling function finite and regular throughout the entire time evolution.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 9","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14796-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145100652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Generalized Bronnikov–Ellis wormhole with nonlinear electromagnetic field 具有非线性电磁场的广义Bronnikov-Ellis虫洞

IF 4.8 2区物理与天体物理

The European Physical Journal C Pub Date : 2025-09-21 DOI: 10.1140/epjc/s10052-025-14729-2

Xin Su, Chen-Hao Hao, Tie-Feng Fang, Yong-Qiang Wang

引用次数: 0

Some thermal properties of ideal gas 理想气体的一些热性质

IF 4.8 2区物理与天体物理

The European Physical Journal C Pub Date : 2025-09-20 DOI: 10.1140/epjc/s10052-025-14730-9

Rajesh Kumar Gupta, Meenu

{"title":"Some thermal properties of ideal gas","authors":"Rajesh Kumar Gupta,  Meenu","doi":"10.1140/epjc/s10052-025-14730-9","DOIUrl":"10.1140/epjc/s10052-025-14730-9","url":null,"abstract":"<div><p>In this article, we investigate the thermal properties of non-relativistic many-body systems at finite temperatures and chemical potential. We compute the one-point function of various operators constructed out of the basic fields in ideal bosonic and fermionic many-body systems. The one-point function is non-zero only for operators with zero particle numbers. We investigate these operators in <span>(mathbb R^d)</span> and <span>(mathbb R^d_{+})</span>, i.e. a flat space with a planar boundary. Furthermore, we compute the Green’s function and using the operator product expansion, we express it in terms of the thermal one-point function of the higher spin currents. On <span>(mathbb R^d_{+})</span>, the operator product expansion allows to express the bulk-bulk Green’s function in terms of the thermal Green’s function of the boundary operators. We also study the ideal system by placing it on curved spatial surfaces, specifically spherical surfaces. We compute the partition function and Green’s function on spheres, squashed-sphere and hemispheres. Finally, we compute the large radius corrections to the partition function and Green’s function by expanding in the large radius limit.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 9","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14730-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145090621","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Lepton flavor violating decays (l_jrightarrow l_igamma ,) (l_j rightarrow 3l_i) and (mu rightarrow e+ qbar{q}) in the N-B-LSSM N-B-LSSM中轻子风味违反衰变(l_jrightarrow l_igamma ,)(l_j rightarrow 3l_i)和(mu rightarrow e+ qbar{q})

IF 4.8 2区物理与天体物理

The European Physical Journal C Pub Date : 2025-09-20 DOI: 10.1140/epjc/s10052-025-14762-1

Rong-Zhi Sun, Shu-Min Zhao, Ming-Yue Liu, Xing-Yu Han, Song Gao, Xing-Xing Dong

{"title":"Lepton flavor violating decays (l_jrightarrow l_igamma ,) (l_j rightarrow 3l_i) and (mu rightarrow e+ qbar{q}) in the N-B-LSSM","authors":"Rong-Zhi Sun, Shu-Min Zhao, Ming-Yue Liu, Xing-Yu Han, Song Gao, Xing-Xing Dong","doi":"10.1140/epjc/s10052-025-14762-1","DOIUrl":"10.1140/epjc/s10052-025-14762-1","url":null,"abstract":"<div><p>The N-B-LSSM is an extension of the minimal supersymmetric Standard Model (MSSM) with the addition of three singlet new Higgs superfields and right-handed neutrinos, whose local gauge group is <span>(SU(3)_Ctimes SU(2)_Ltimes U(1)_Ytimes U(1)_{B-L}.)</span> In the N-B-LSSM, we study lepton flavor violating decays <span>(l_jrightarrow l_igamma ,)</span> <span>(l_j rightarrow 3l_i)</span> and <span>(mu rightarrow e+ qbar{q})</span> <span>((j=tau ,mu ,~i=mu ,e)</span> and <span>(ine j).)</span> Based on the current experimental limits, we carry out detailed parameter scanning and numerical calculation to analyse the effects of different sensitive parameters on lepton flavor violation (LFV) in the N-B-LSSM. The numerical results show that the non-diagonal elements involving the initial and final leptons are main sensitive parameters and LFV sources. This work is conducive to exploring new physics (NP) beyond the Standard Model (SM).\u0000\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 9","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14762-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145090623","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

On the red-shift emission from the black hole horizons replicas 从黑洞视界复制的红移辐射

IF 4.8 2区物理与天体物理

The European Physical Journal C Pub Date : 2025-09-20 DOI: 10.1140/epjc/s10052-025-14746-1

D. Pugliese, Z. Stuchlík

{"title":"On the red-shift emission from the black hole horizons replicas","authors":"D. Pugliese, Z. Stuchlík","doi":"10.1140/epjc/s10052-025-14746-1","DOIUrl":"10.1140/epjc/s10052-025-14746-1","url":null,"abstract":"<div><p>We examine the red-shift emission from special orbits (<i>horizons replicas</i>) where photons have the same angular velocity, in magnitude, as those of the Kerr black hole (<b>BH</b>) Killing horizons. We focus on two particular contexts of special significance for their observational implications. A set of these orbits is located in the <b>BH</b> photons shell. Therefore the analysis also connects the red-shifting or blue-shifting from replicas (defined through the <b>BH</b> light surfaces) to the <b>BH</b> shadow boundaries. We then concentrate on the equatorial, general relativistic, axially symmetric accretion disks, orbiting around the central attractor. In the analysis we adopted in particular the Polish doughnut models of geometrically thick toroids, to investigate the signals frequency-shifting from the horizons replica as related to the disks surface, inner edge and accretion flows. The findings map the red-shifting and blue-shifting regions of the signals in dependence to the photons impact parameter, view-angle, angular velocity of the emitter and <b>BH</b> spin. Co-rotating and counter-rotating replica could be identified through the red-shifting or blue-shifting of the emitted signals from the mapped regions.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 9","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14746-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145090617","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The sound of quintessence: analogue Kiselev acoustic black holes 声音的精髓：模拟基谢列夫声学黑洞

IF 4.8 2区物理与天体物理

The European Physical Journal C Pub Date : 2025-09-20 DOI: 10.1140/epjc/s10052-025-14789-4

Luis C. N. Santos, H. S. Vieira, Franciele M. da Silva, V. B. Bezerra

{"title":"The sound of quintessence: analogue Kiselev acoustic black holes","authors":"Luis C. N. Santos, H. S. Vieira, Franciele M. da Silva, V. B. Bezerra","doi":"10.1140/epjc/s10052-025-14789-4","DOIUrl":"10.1140/epjc/s10052-025-14789-4","url":null,"abstract":"<div><p>In this work, we demonstrate that the geometry of a spherically symmetric black hole surrounded by a Kiselev anisotropic fluid can be effectively mimicked by an experimental setup as the ones used to investigate some physical phenomena associated with acoustic black holes. Thus, we construct the metric describing Kiselev acoustic black holes by using the Gross–Pitaevskii theory and present a general analytical solution that encompasses, as particular cases, several classes of geometries associated with black holes. This unified framework allows for the description of a wide variety of analogue spacetimes, including new analogue geometries that have not been previously explored in the literature. Then, we examine the behavior of scalar field perturbations in this background by solving the massless Klein–Gordon equation. Depending on the boundary conditions between the acoustic event horizon and infinity, we obtain the quasinormal and quasibound spectra. This study opens up avenues for experimental investigation within the context of analog gravity models, by offering new possibilities to simulate and study black hole phenomena in laboratory settings.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 9","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14789-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145090618","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Stochastic automatic differentiation and the signal to noise problem 随机自动微分与信噪问题

IF 4.8 2区物理与天体物理

The European Physical Journal C Pub Date : 2025-09-20 DOI: 10.1140/epjc/s10052-025-14690-0

G. Catumba, A. Ramos

引用次数: 0

Analyzing the transport coefficients and observables of a rotating QGP medium in kinetic theory framework with a novel approach to the collision integral 用一种新的碰撞积分方法分析旋转QGP介质的输运系数和观测值

IF 4.8 2区物理与天体物理

The European Physical Journal C Pub Date : 2025-09-20 DOI: 10.1140/epjc/s10052-025-14758-x

Shubhalaxmi Rath, Sadhana Dash

{"title":"Analyzing the transport coefficients and observables of a rotating QGP medium in kinetic theory framework with a novel approach to the collision integral","authors":"Shubhalaxmi Rath, Sadhana Dash","doi":"10.1140/epjc/s10052-025-14758-x","DOIUrl":"10.1140/epjc/s10052-025-14758-x","url":null,"abstract":"<div><p>In the present work, we have studied how the rotation of the QGP medium affects the transport coefficients and observables in heavy ion collisions. For the noncentral collisions, although most of the angular momentum gets carried away by the spectators, there still remains a finite angular momentum with a finite range of angular velocity, which thus incites rotation in the produced matter. As a result, various properties of the QGP medium including its transport properties are most likely to be modulated by the rotation. We have calculated the transport coefficients and observables, such as the electrical conductivity, the thermal conductivity, the Knudsen number, the elliptic flow, the specific heat at constant pressure, the specific heat at constant volume, the trace anomaly, the thermal diffusion constant and the isothermal compressibility using the kinetic theory to see the effect of rotation on them. In particular, we have used the novel relaxation time approximation for the collision integral in the relativistic Boltzmann transport equation to derive the transport coefficients and compared them with their values in the relaxation time approximation within the kinetic theory approach in conjunction with the finite angular velocity. We have found that the emergence of angular velocity enhances the flow of charge and heat in the medium. Further, as compared to the relaxation time approximation, the electrical and the thermal conductivities have smaller values in the novel relaxation time approximation and these differences between the conductivities in the said approximations are more pronounced at high temperatures than at low temperatures. Furthermore, all the aforesaid observables are found to be sensitive to the rotation of the QGP medium.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 9","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14758-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145090624","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Casimir effect for quantum field theory in networks 网络中量子场论中的卡西米尔效应

IF 4.8 2区物理与天体物理

The European Physical Journal C Pub Date : 2025-09-20 DOI: 10.1140/epjc/s10052-025-14781-y

Tian-Ming Zhao, Rong-Xin Miao

引用次数: 0

Revisiting the Immirzi parameter: Landauer’s principle and alternative entropy frameworks in loop quantum gravity 重新审视Immirzi参数：兰道尔原理和循环量子引力中的熵框架

IF 4.8 2区物理与天体物理

The European Physical Journal C Pub Date : 2025-09-19 DOI: 10.1140/epjc/s10052-025-14783-w

Everton M. C. Abreu, Jorge Ananias Neto, Ronaldo Thibes

{"title":"Revisiting the Immirzi parameter: Landauer’s principle and alternative entropy frameworks in loop quantum gravity","authors":"Everton M. C. Abreu, Jorge Ananias Neto, Ronaldo Thibes","doi":"10.1140/epjc/s10052-025-14783-w","DOIUrl":"10.1140/epjc/s10052-025-14783-w","url":null,"abstract":"<div><p>This paper investigates the implications from area quantization in Loop Quantum Gravity, particularly focusing on the application of the Landauer principle – a fundamental thermodynamic concept establishing a connection between information theory and thermodynamics. By leveraging the Landauer principle in conjunction with the Bekenstein–Hawking entropy law, we derive the usual value for the Immirzi parameter precisely, <span>(gamma = ln 2/(pi sqrt{3}))</span>, without using the typical procedure that involves the Boltzmann–Gibbs entropy. Furthermore, following an analogous procedure, we derive a modified expression for the Immirzi parameter aligned with Barrow’s entropy formulation. Our analysis also yields a new expression for the Immirzi parameter consistent with a corresponding modified Kaniadakis entropy for black hole entropy further illustrating, along with Barrow’s entropy, the applicability of Landauer’s principle in alternative statistical contexts within black hole physics.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 9","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14783-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145078882","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0