General Relativity and Gravitation最新文献_第4页

The Dirac equation in general relativity and the 3+1 formalism 广义相对论中的狄拉克方程和3+1形式

IF 2.8 4区物理与天体物理

General Relativity and Gravitation Pub Date : 2025-08-14 DOI: 10.1007/s10714-025-03460-8

Miguel Alcubierre

引用次数: 0

Bound on generalized uncertainty principle parameter from nuclear matter and slow rotating neutron stars 从核物质和慢旋转中子星的广义不确定原理参数的约束

IF 2.8 4区物理与天体物理

General Relativity and Gravitation Pub Date : 2025-08-08 DOI: 10.1007/s10714-025-03457-3

M. H. Al Ghifari, H. S. Ramadhan, H. Alatas, A. Sulaksono

{"title":"Bound on generalized uncertainty principle parameter from nuclear matter and slow rotating neutron stars","authors":"M. H. Al Ghifari, H. S. Ramadhan, H. Alatas, A. Sulaksono","doi":"10.1007/s10714-025-03457-3","DOIUrl":"10.1007/s10714-025-03457-3","url":null,"abstract":"<div><p>Constraining the Generalized Uncertainty Principle (GUP) parameter is crucial for probing potential quantum gravity effects in regimes that extend beyond the Planck scale. In this study, we place bounds on the <span>(beta )</span> parameter, associated with the widely studied quadratic GUP model, using existing experimental data from nuclear matter and results from chiral effective field theory (<span>(chi )</span>EFT) calculations. We also assess the compatibility of neutron star (NS) matter prediction based on those extracted from NS observations. The quadratic GUP model shares the same dispersion relation as a specific version of Double Special Relativity (DSR), establishing a connection between one of the rainbow gravity (RG) parameters and the quadratic GUP parameter. We then explore NS properties within the RG framework, defining <span>(X = E/E_p)</span> alongside <span>(beta )</span>. Therefore, we calculate the predictions for slow-rotating NS using the RG effective metric and compare these results with existing observational data. From our analysis, we obtain an upper bound of <span>(beta = 1.5 times 10^{-7})</span> based on nuclear matter and neutron star matter data. We also find a non-zero lower bound of <span>(beta = -1.5 times 10^{-7})</span>. When using <span>(beta = 1.5 times 10^{-7})</span> within the RG framework, the maximum mass prediction is lower than the constraints derived from the NICER data. In fact, rather than increasing, the parameter <i>X</i> further decreases the maximum mass prediction. However, when we set <span>(beta = -1.5 times 10^{-7})</span> and <span>(X = 10^{-38.5})</span>, the maximum neutron star mass remains consistent with NICER and other astrophysical constraints. Our results show that slowly rotating NS favor negative <span>(beta )</span> within this framework.</p></div>","PeriodicalId":578,"journal":{"name":"General Relativity and Gravitation","volume":"57 8","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144924594","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Phase space analysis of Rényi Holographic dark energy model r<s:1>尼全息暗能量模型的相空间分析

IF 2.8 4区物理与天体物理

General Relativity and Gravitation Pub Date : 2025-08-06 DOI: 10.1007/s10714-025-03454-6

Santanu Das, Nilanjana Mahata

引用次数: 0

Mass-Gap Neutron Stars from Vector f(R) Gravity Inflationary Deformations 从矢量f(R)重力暴胀变形看质量间隙中子星

IF 2.8 4区物理与天体物理

General Relativity and Gravitation Pub Date : 2025-08-05 DOI: 10.1007/s10714-025-03451-9

V. K. Oikonomou

{"title":"Mass-Gap Neutron Stars from Vector f(R) Gravity Inflationary Deformations","authors":"V. K. Oikonomou","doi":"10.1007/s10714-025-03451-9","DOIUrl":"10.1007/s10714-025-03451-9","url":null,"abstract":"<div><p>The latest observations from the LIGO-Virgo indicated the existence of mass-gap region astrophysical objects. This is a rather sensational observation and there are two possibilities for the nature of these mass-gap region astrophysical objects, these are either small black holes that result from the mergers of ordinary mass neutron stars, or these are heavy neutron stars. In the line of research implied by the former possibility, in this work we shall examine the implied neutron star phenomenology from vector <i>f</i>(<i>R</i>) gravity inflationary models. These theories are basically scalar-tensor deformations of the Starobinsky inflationary model. We shall present the essential features of cosmologically viable and non-viable deformations of the Starobinsky model, originating from vector <i>f</i>(<i>R</i>) gravity inflationary theories, and we indicate which models and for which equations of state provide a viable neutron star phenomenology. We solve the Tolman-Oppenheimer-Volkov equations using a robust double shooting LSODA python based code, for the following piecewise polytropic equations of state: the WFF1, the SLy, the APR, the MS1, the AP3, the AP4, the ENG, the MPA1 and the MS1b. We confront the resulting phenomenology with several well-known neutron star constraints, and we indicate which equation of state and model fits the phenomenological constraints. A remarkable feature, also known from other inflationary attractor models, is that the MPA1 is the equation of state which is most nicely fitted to the constraints, for all the theoretical models used, and actually the maximum mass for this equation of state is well inside the mass-gap region. Another mentionable feature that stroked us with surprise is the fact that even cosmologically non-viable inflationary models produced a viable neutron star phenomenology, which most likely has to be a model-dependent feature.</p></div>","PeriodicalId":578,"journal":{"name":"General Relativity and Gravitation","volume":"57 8","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144924643","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A string theoretic derivation of Gibbons-Hawking entropy 长臂猿-霍金熵的弦理论推导。

IF 2.8 4区物理与天体物理

General Relativity and Gravitation Pub Date : 2025-08-02 DOI: 10.1007/s10714-025-03446-6

Gia Dvali

引用次数: 0

The fundamental physical importance of generic off-diagonal solutions and Grigori Perelman entropy in the Einstein gravity theory 爱因斯坦引力理论中一般非对角解和Grigori Perelman熵的基本物理重要性

IF 2.8 4区物理与天体物理

General Relativity and Gravitation Pub Date : 2025-08-01 DOI: 10.1007/s10714-025-03456-4

Sergiu I. Vacaru, Elşen Veli Veliev

{"title":"The fundamental physical importance of generic off-diagonal solutions and Grigori Perelman entropy in the Einstein gravity theory","authors":"Sergiu I. Vacaru, Elşen Veli Veliev","doi":"10.1007/s10714-025-03456-4","DOIUrl":"10.1007/s10714-025-03456-4","url":null,"abstract":"<div><p>The gravitational field equations in general relativity (GR) consist of a sophisticated system of nonlinear partial differential equations. Solving such equations in some generic off-diagonal forms is usually a hard analytic or numeric task. Physically important solutions in GR were constructed using diagonal ansatz for metrics with maximum 4 independent coefficients. The Einstein equations can be solved in exact or parametric forms determined by some integration constants for corresponding assumptions on spherical or cylindric spacetime symmetries. The anholonomic frame and connection deformation method allows us to construct generic off-diagonal solutions described by 6 independent coefficients of metrics depending, in general, on all spacetime coordinates. New types of exact and parametric solutions are determined by generating and integration functions and (effective) generating sources. They may describe vacuum gravitational and matter fields solitonic hierarchies; locally anisotropic polarizations of physical constants for black holes, wormholes, black toruses, or cosmological solutions; various types of off-diagonal deformations of horizons etc. The additional degrees of freedom (related to off-diagonal coefficients) can be used to describe dark energy and dark matter configurations and elaborate locally anisotropic cosmological scenarios. In general, the generic off-diagonal solutions do not involve certain hypersurface or holographic configurations and can’t be described in the framework of the Bekenstein-Hawking thermodynamic paradigm. We argue that generalizing the concept of G. Perelman’s entropy for relativistic Ricci flows allows us to define and compute geometric thermodynamic variables for all possible classes of solutions in GR.</p></div>","PeriodicalId":578,"journal":{"name":"General Relativity and Gravitation","volume":"57 8","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144924662","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Experimental observation of a Rindler horizon 伦德勒视界的实验观察

IF 2.8 4区物理与天体物理

General Relativity and Gravitation Pub Date : 2025-07-31 DOI: 10.1007/s10714-025-03453-7

Morgan H. Lynch

引用次数: 0

Observer dependence of quantum effective potential: insights from a Rindler observer 量子有效势的观察者依赖：来自伦德勒观察者的见解

IF 2.8 4区物理与天体物理

General Relativity and Gravitation Pub Date : 2025-07-23 DOI: 10.1007/s10714-025-03449-3

Pallab Basu, S. R. Haridev, Prasant Samantray

引用次数: 0

Observational restrictions and slow-roll D-brane inflation in the special (F(phi ,T)) gravity 特殊$$F(phi ,T)$$重力下的观测限制和慢滚d膜膨胀

IF 2.8 4区物理与天体物理

General Relativity and Gravitation Pub Date : 2025-07-22 DOI: 10.1007/s10714-025-03448-4

Feyzollah Younesizadeh, Davoud Kamani

引用次数: 0

Gravitational self-force with hyperboloidal slicing and spectral methods 重力自作用力的双曲面切片和谱方法

IF 2.8 4区物理与天体物理

General Relativity and Gravitation Pub Date : 2025-07-19 DOI: 10.1007/s10714-025-03443-9

Benjamin Leather

{"title":"Gravitational self-force with hyperboloidal slicing and spectral methods","authors":"Benjamin Leather","doi":"10.1007/s10714-025-03443-9","DOIUrl":"10.1007/s10714-025-03443-9","url":null,"abstract":"<div><p>We present a novel approach for calculating the gravitational self-force (GSF) in the Lorenz gauge, employing hyperboloidal slicing and spectral methods. Our method builds on the previous work that applied hyperboloidal surfaces and spectral approaches to a scalar-field toy model [Phys. Rev. D 105, 104033 (2022)], extending them to handle gravitational perturbations. Focusing on first-order metric perturbations, we address the construction of the hyperboloidal foliation, detailing the minimal gauge choice. The Lorenz gauge is adopted to facilitate well-understood regularisation procedures, which are essential for obtaining physically meaningful GSF results. We calculate the Lorenz gauge metric perturbation for a secondary on a quasicircular orbit in a Schwarzschild background via a (known) gauge transformation from the Regge-Wheeler gauge. Our approach yields a robust framework for obtaining the metric perturbation components needed to calculate key physical quantities, such as radiative fluxes, the Detweiler redshift, and self-force corrections. Furthermore, the compactified hyperboloidal approach allows us to efficiently calculate the metric perturbation throughout the entire spacetime. This work thus establishes a foundational methodology for future second-order GSF calculations within this gauge, offering computational efficiencies through spectral methods.</p></div>","PeriodicalId":578,"journal":{"name":"General Relativity and Gravitation","volume":"57 7","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10714-025-03443-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144924597","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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