The European Physical Journal C最新文献

Extracting energy from plunging region of a Kerr-Taub-NUT black hole by magnetic reconnection 利用磁重联从克尔-陶布-努特黑洞俯冲区提取能量

IF 4.8 2区物理与天体物理

The European Physical Journal C Pub Date : 2025-10-11 DOI: 10.1140/epjc/s10052-025-14894-4

Zhengwei Cheng, Songbai Chen, Jiliang Jing

引用次数: 0

Probing thermodynamic phase transitions via Lyapunov exponent in AdS black hole with perfect fluid dark matter 利用Lyapunov指数探测具有完美流体暗物质的AdS黑洞热力学相变

IF 4.8 2区物理与天体物理

The European Physical Journal C Pub Date : 2025-10-11 DOI: 10.1140/epjc/s10052-025-14816-4

R. H. Ali, Xiao-Mei Kuang

{"title":"Probing thermodynamic phase transitions via Lyapunov exponent in AdS black hole with perfect fluid dark matter","authors":"R. H. Ali, Xiao-Mei Kuang","doi":"10.1140/epjc/s10052-025-14816-4","DOIUrl":"10.1140/epjc/s10052-025-14816-4","url":null,"abstract":"<div>We revisit the large-small black hole phase transitions in Reissner–Nordström (RN) AdS black holes coupled with perfect fluid dark matter. Besides the free energy, we examine the features of Lyapunov exponents for both massive and massless particles, which can characterize the chaos and instability of a particle’s motion orbiting the black hole. The presence of dark matter increases the critical temperature, making it more challenging for the phase transition to occur in comparison to an RN AdS black hole. Our analysis reveals that during the transition in phase structure, the Lyapunov exponents manifest multivalued behavior, with exclusive branches associated with distinct phases of black holes. Additionally, we observe that the discontinuous changes in the Lyapunov exponent act as an order parameter, characterized by a critical exponent of 1/2 near the critical point. These phenomena are similar to those found in RN AdS black holes and further suggest that the Lyapunov exponent can provide a valuable framework for probing the phase structure of black holes.\u0000</div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 10","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14816-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145256808","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

Primordial black holes and scalar induced gravitational waves from sound speed resonance in non-minimal derivative coupling inflation model 原始黑洞与非极小导数耦合膨胀模型中声速共振的标量诱导引力波

IF 4.8 2区物理与天体物理

The European Physical Journal C Pub Date : 2025-10-10 DOI: 10.1140/epjc/s10052-025-14840-4

Li-Shuai Wang, Qiong-Tao Xie, Li-Yang Chen

{"title":"Primordial black holes and scalar induced gravitational waves from sound speed resonance in non-minimal derivative coupling inflation model","authors":"Li-Shuai Wang, Qiong-Tao Xie, Li-Yang Chen","doi":"10.1140/epjc/s10052-025-14840-4","DOIUrl":"10.1140/epjc/s10052-025-14840-4","url":null,"abstract":"<div>We investigate an inflationary model with a non-minimal derivative coupling, where the coupling function contains both constant and periodic components. On large scales, the model is in excellent agreement with the latest Planck-ACT-LiteBIRD-BICEP/Keck 2018 (P-ACT-LB-BK18) observations. On small scales, the periodic component induces a sound-speed resonance mechanism that significantly amplifies curvature perturbations, resulting in the production of primordial black holes (PBHs). By incorporating nonlinear effects in the PBH abundance calculation, we find that the resulting PBHs can account for the majority of dark matter in the Universe. Furthermore, the PBH formation process generates scalar-induced gravitational waves (SIGWs) with a characteristic multi-peak spectral shape, which may be detectable by future space-based detectors such as LISA, Taiji, and TianQin. The model also predicts a high-frequency stochastic gravitational-wave background (SGWB) from PBH binary mergers. A combined detection of SIGWs and high-frequency gravitational waves (GWs) in future experiments would provide a direct and testable probe of this inflationary scenario.\u0000</div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 10","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14840-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145256222","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

Cosmic acceleration from nothing 宇宙从无到有加速

IF 4.8 2区物理与天体物理

The European Physical Journal C Pub Date : 2025-10-10 DOI: 10.1140/epjc/s10052-025-14887-3

Michael R. R. Good, Eric V. Linder

引用次数: 0

On FLRW reductions of (N=1) supergravity 关于(N=1)超重力的FLRW缩减

IF 4.8 2区物理与天体物理

The European Physical Journal C Pub Date : 2025-10-10 DOI: 10.1140/epjc/s10052-025-14874-8

Nephtalí Eliceo Martínez-Pérez, Cupatitzio Ramírez Romero

引用次数: 0

General formulas for loop-induced decays of (A rightarrow Zgamma gamma ) and their applications (A rightarrow Zgamma gamma )环致衰减的一般公式及其应用

IF 4.8 2区物理与天体物理

The European Physical Journal C Pub Date : 2025-10-10 DOI: 10.1140/epjc/s10052-025-14852-0

Dzung Tri Tran, Thanh Huy Nguyen, Khiem Hong Phan

{"title":"General formulas for loop-induced decays of (A rightarrow Zgamma gamma ) and their applications","authors":"Dzung Tri Tran, Thanh Huy Nguyen, Khiem Hong Phan","doi":"10.1140/epjc/s10052-025-14852-0","DOIUrl":"10.1140/epjc/s10052-025-14852-0","url":null,"abstract":"<div>Within the framework of the Standard Model Higgs extensions, including the Two-Higgs-Doublet Model with vector-like fermions and the Triplet-Higgs Model, we derive general one-loop contributions to the rare decay process (A rightarrow Z gamma gamma .) The analytical expressions are formulated with Passarino–Veltman scalar functions, which represent the scalar coefficients of one-loop Lorentz-covariant tensor integrals. These functions are written in accordance with the input conventions of the LoopTools and Collier packages, facilitating the efficient numerical generation of decay rates and their distributions using these computational tools. As part of our phenomenological study, we examine the branching ratios of this decay channel within the viable parameter space of the considered models. Our results indicate that the branching ratio can reach ({mathcal {O}}(10^{-3})) in the Two-Higgs-Doublet Model and ({mathcal {O}}(10^{-2})) in the Triplet-Higgs Model at specific points within the allowed parameter regions. Furthermore, the inclusion of vector-like fermions in the loop leads to a significant modification of the partial decay rates, with an observed variation of approximately (5%.) Additionally, we explore the dependence of the branching ratios on key model parameters, including the charged Higgs mass, mixing angles, and the soft-breaking scale, providing deeper insights into the phenomenological implications of these Higgs-extended frameworks.\u0000</div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 10","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14852-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145256519","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

Designing wormholes in novel power-law f(R): a mathematical approach with a linear equation of state 在新的幂律f(R)中设计虫洞：一种线性状态方程的数学方法

IF 4.8 2区物理与天体物理

The European Physical Journal C Pub Date : 2025-10-10 DOI: 10.1140/epjc/s10052-025-14863-x

Subhasis Nalui, Subhra Bhattacharya

{"title":"Designing wormholes in novel power-law f(R): a mathematical approach with a linear equation of state","authors":"Subhasis Nalui, Subhra Bhattacharya","doi":"10.1140/epjc/s10052-025-14863-x","DOIUrl":"10.1140/epjc/s10052-025-14863-x","url":null,"abstract":"<div>We consider the inhomogeneous Morris–Thorne wormhole metric with matter tensors characterised by a novel linear equation of state in f(R) gravity. Using the Einstein’s field equations in metric f(R) gravity we model solutions for both wormhole as well as f(R) gravity. We obtain four different wormhole models, two wormholes are characterised by solid angle deficit, three are not asymptotically extendible, while one is asymptotically flat with zero tidal force. These are supported by four different power law f(R) models. The parameter space of the models can support both null energy conditions (NEC) satisfying as well as violating wormhole. In case of NEC satisfying matter, the associated f(R) is ghost. The f(R) models obtained have been independently substantiated for cosmological feasibility and valid parameter space was obtained corresponding to cosmologically viable f(R). Suitable scalar-tensor representation of the corresponding f(R) models have been presented using the correspondence of f(R) gravity with Brans–Dicke (BD) theory of gravity. The robustness of the wormhole solutions were further analysed with the BD scalar fields in the hybrid metric-Palatini gravity, which showed excellent results. Lastly as an independent astrophysical probe for the wormhole we have obtained the location of their photon spheres and have connected them with the Herrera Complexity factor in f(R). Our results show that the relation between the complexity factor and existence of photon spheres remains fundamentally unaltered in f(R) as compared to Einstein’s gravity.\u0000</div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 10","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14863-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145256629","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

Imaging characteristics of Frolov black holes under different accretion models 不同吸积模型下Frolov黑洞的成像特征

IF 4.8 2区物理与天体物理

The European Physical Journal C Pub Date : 2025-10-10 DOI: 10.1140/epjc/s10052-025-14715-8

Jia-Shuo Li, Sen Guo, Yu-Xiang Huang, Qing-Quan Jiang, Kai Lin

{"title":"Imaging characteristics of Frolov black holes under different accretion models","authors":"Jia-Shuo Li, Sen Guo, Yu-Xiang Huang, Qing-Quan Jiang, Kai Lin","doi":"10.1140/epjc/s10052-025-14715-8","DOIUrl":"10.1140/epjc/s10052-025-14715-8","url":null,"abstract":"<div>We simulate the light trajectories of the Frolov black hole and investigate the image characteristics of the black hole by performing numerical calculations and using light ray tracing methods. It is observed that rising values of parameters l and q lead to a smaller event horizon radius for the Frolov black hole and weaken its ability to deflect light rays. We discuss the image characteristics under the background of the spherical accretion model and the thin disk accretion model. It is found that the static spherical accretion model yields a higher observational intensity compared to the infalling spherical accretion model. In the geometrically thin and optically thin accretion disk, direct emission is the main source of light intensity, while the contribution from photon ring emission is weaker. In the model of a slim disk with optically thick accretion flow, images observed at various inclination angles exhibit notable differences. These results indicate that when both parameters l and q are large, the appearance of the Frolov black hole differs significantly from that of the Schwarzschild black hole. Therefore, in future observational studies, the image will become an important tool for distinguishing between these two types of black holes.\u0000\u0000</div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 10","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14715-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145256523","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

Ultralight dilaton oscillations and the cosmological constant 超轻膨胀振荡和宇宙常数

IF 4.8 2区物理与天体物理

The European Physical Journal C Pub Date : 2025-10-09 DOI: 10.1140/epjc/s10052-025-14846-y

Abdellah Touati

引用次数: 0

Chaos of charged particles near a renormalized group improved Kerr black hole in an external magnetic field 外加磁场中重整化群附近带电粒子的混沌改进了克尔黑洞

IF 4.8 2区物理与天体物理

The European Physical Journal C Pub Date : 2025-10-09 DOI: 10.1140/epjc/s10052-025-14853-z

Junjie Lu, Xin Wu

{"title":"Chaos of charged particles near a renormalized group improved Kerr black hole in an external magnetic field","authors":"Junjie Lu, Xin Wu","doi":"10.1140/epjc/s10052-025-14853-z","DOIUrl":"10.1140/epjc/s10052-025-14853-z","url":null,"abstract":"<div>In a quantum theory of gravity, a renormalization group improved Kerr metric is obtained from the Kerr metric, where the Newton gravitational constant is modified as a function of the radial distance. The motion of neutral test particles in this metric is integrable. However, the dynamics of charged test particles is nonintegrable when an external asymptotically homogeneous magnetic field exists in the vicinity of the black hole. The transition from regular dynamics to chaotic dynamics is numerically traced as one or two dynamical parameters vary. From a statistical point of view, the strength of chaos is typically enhanced as both the particle energy and the magnetic field increase, but it is weakened with increasing the particle angular momentum and the black hole spin. In particular, an increase of the quantum corrected parameter weakens the extent of chaos. This is because the running Newton gravity constant effectively weakens the central gravitational attraction and results in decreasing sensitivity to initial conditions.\u0000</div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 10","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14853-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145256135","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