General Relativity and Gravitation最新文献_第3页

Critical enhancement of Hawking radiation in geometrically deformed dilaton black holes 几何变形膨胀黑洞中霍金辐射的临界增强

IF 3 4区物理与天体物理

General Relativity and Gravitation Pub Date : 2026-09-01 DOI: 10.1007/s10714-026-03607-1

Reza Baghbani

{"title":"Critical enhancement of Hawking radiation in geometrically deformed dilaton black holes","authors":"Reza Baghbani","doi":"10.1007/s10714-026-03607-1","DOIUrl":"10.1007/s10714-026-03607-1","url":null,"abstract":"<div><p>We investigate Hawking radiation near the thermodynamic critical point of a four-dimensional dilaton black hole with a geometrically deformed angular sector <span>(R(r)=(r/r_0)^N)</span>. Treating the deformation exponent <i>N</i> as an active control parameter, we locate a second-order phase transition governed by mean-field critical exponents, whose amplitudes are explicitly modulated by <i>N</i>. Solving the Klein–Gordon equation, we derive the exact effective scattering potential and propose a phenomenological Breit–Wigner resonance model for the greybody factor near criticality, motivated by the divergence of thermodynamic response functions. Quasinormal mode analysis in the eikonal limit establishes a correspondence with the unstable photon orbit, and third-order WKB computations of the QNM spectra indicate that <i>N</i> modulates both the ringdown frequency and Lyapunov damping. All thermodynamic, dynamical, and radiative quantities reduce smoothly to the Reissner–Nordström–AdS limit as <span>(N rightarrow 0^-)</span> and <span>(alpha rightarrow 0)</span>. Our results suggest that geometric warping may provide a tunable framework for probing quantum gravitational observables, though direct numerical computation of the greybody factor is required to confirm the predicted resonant enhancement.</p></div>","PeriodicalId":578,"journal":{"name":"General Relativity and Gravitation","volume":"58 9","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148883490","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

On non-vacuum black holes in new general relativity 关于新广义相对论中的非真空黑洞

IF 3 4区物理与天体物理

General Relativity and Gravitation Pub Date : 2026-09-01 DOI: 10.1007/s10714-026-03605-3

D. F. López, A. A. Coley, B. Yildirim

{"title":"On non-vacuum black holes in new general relativity","authors":"D. F. López, A. A. Coley, B. Yildirim","doi":"10.1007/s10714-026-03605-3","DOIUrl":"10.1007/s10714-026-03605-3","url":null,"abstract":"<div><p>New general relativity (NGR) is a torsion-based modification of general relativity whose Lagrangian depends on three free parameters, <span>((c_{a}, c_{v}, c_{t}))</span>. A subset of the parameter space is physically admissible, namely that which simultaneously ensures ghost-freedom, propagation of a spin-2 mode, and a consistent Newtonian limit. In this work we analyze static and spherically symmetric configurations in NGR, both in vacuum and in the presence of a perfect fluid and an electromagnetic field, under the assumption of the existence of a local black-hole horizon. We find that the mere existence of such configurations forces the free parameters into regions associated with known pathological models: theories that either contain ghost instabilities, do not propagate a spin-2 mode, or lack a Newtonian limit. The remaining geometries are regular at the horizon, so the obstruction is not a breakdown of the geometry but a breakdown of the underlying theory. We therefore conclude that, within the static, spherically symmetric, perturbative framework examined here, NGR does not admit physically meaningful non-trivial black holes distinct from those of the teleparallel equivalent of general relativity.</p></div>","PeriodicalId":578,"journal":{"name":"General Relativity and Gravitation","volume":"58 9","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148883491","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

Hamiltonian surface charges in general parallel relativity 广义平行相对论中的哈密顿表面电荷

IF 3 4区物理与天体物理

General Relativity and Gravitation Pub Date : 2026-09-01 DOI: 10.1007/s10714-026-03602-6

Tomi S. Koivisto

引用次数: 0

Finite 4-D Gauss–Bonnet quantum corrections from matter-graviton interactions in a curved background 弯曲背景下物质-重子相互作用的有限四维高斯-博内量子修正

IF 3 4区物理与天体物理

General Relativity and Gravitation Pub Date : 2026-08-31 DOI: 10.1007/s10714-026-03603-5

Apurv Keer, S. Shankaranarayanan

{"title":"Finite 4-D Gauss–Bonnet quantum corrections from matter-graviton interactions in a curved background","authors":"Apurv Keer, S. Shankaranarayanan","doi":"10.1007/s10714-026-03603-5","DOIUrl":"10.1007/s10714-026-03603-5","url":null,"abstract":"<div><p>The Glavan–Lin proposal for 4D Einstein–Gauss–Bonnet (EGB) gravity introduces a singular dimensional scaling to bypass Lovelock’s theorem, though its fundamental origin remains debated. In this work, we demonstrate that this specific dimension-dependent scaling naturally emerges from the one-loop self-energy corrections of gravitons. By employing real-space techniques to evaluate graviton interactions with minimally coupled scalar and electromagnetic fields <i>in a de Sitter background</i>, we show that the <span>(1/(D-4))</span> pole from dimensional regularization naturally yields a term proportional to the Gauss–Bonnet invariant. Importantly, because the Gauss–Bonnet density is a total derivative in four dimensions, this combination yields a strictly finite quantum correction analogous to the conformal anomaly, rather than a divergent counterterm. We confirm that the true ultraviolet divergences are strictly renormalized by standard quadratic curvature counterterms, specifically the Weyl-squared and Ricci-scalar-squared invariants. Our results indicate that the Glavan–Lin scaling is <i>not an ad-hoc</i> classical limit, but effectively captures a finite, loop-induced quantum feature of the effective action. We discuss the implications of these finite, background-dependent corrections in the early-Universe and their consequences in the strong gravity regime.</p></div>","PeriodicalId":578,"journal":{"name":"General Relativity and Gravitation","volume":"58 9","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148859858","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

Geometric scalar field dynamics and intrinsic vacuum structure on superspace 超空间上的几何标量场动力学与本征真空结构

IF 3 4区物理与天体物理

General Relativity and Gravitation Pub Date : 2026-08-24 DOI: 10.1007/s10714-026-03604-4

Avadhut V. Purohit

{"title":"Geometric scalar field dynamics and intrinsic vacuum structure on superspace","authors":"Avadhut V. Purohit","doi":"10.1007/s10714-026-03604-4","DOIUrl":"10.1007/s10714-026-03604-4","url":null,"abstract":"<div><p>We formulate a geometric scalar field theory on superspace by reinterpreting the ADM Hamiltonian constraint as a covariant dynamical equation for a scalar degree of freedom <span>(Phi [q_{ab}])</span>. Unlike the Wheeler–DeWitt (WdW) wave functional, the resulting framework admits intrinsic evolution in Lorentzian sectors of the DeWitt supermetric, with the conformal variable <span>(zeta sim {(det q_{ab})}^{1/4})</span> acting as an emergent time parameter. The dynamics are governed by a Klein–Gordon (KG) type operator on superspace with curvature-induced coupling <span>(mu ^2 = -sqrt{q},{}^{(3)}!R)</span>, giving rise to geometry-dependent effective potentials together with stable and symmetry-broken sectors. Within Lorentzian regions of superspace, the theory admits a Hamiltonian formulation with an intrinsic oscillator structure. The corresponding Hamiltonian can be diagonalized through a Riccati-type equation, leading to geometry-dependent mode frequencies and a nontrivial deformation of the canonical algebra. Quantization yields locally inequivalent Fock representations and <span>(zeta )</span>-dependent vacuum sectors, implying intrinsic Bogoliubov-type mixing of geometric excitations. In minisuperspace reductions, the framework reproduces time-dependent oscillator dynamics analogous to those in quantum field theory in curved spacetime, while reducing to the standard WdW and free-field limits in appropriate regimes. The theory further generates an effective stress-energy tensor with asymptotic matter-like scaling, indicating that purely geometric superspace dynamics can induce effective emergent matter-like behavior in spacetime.\u0000</p></div>","PeriodicalId":578,"journal":{"name":"General Relativity and Gravitation","volume":"58 8","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148837892","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

Geometric analysis in a Lorentzian setting and the problem of shock development in fluids 洛伦兹环境下的几何分析和流体中的激波发展问题

IF 3 4区物理与天体物理

General Relativity and Gravitation Pub Date : 2026-08-24 DOI: 10.1007/s10714-026-03570-x

Demetrios Christodoulou

引用次数: 0

A note on splitting solutions in (4+1) dimensional quadratic gravity 关于$$4+1$$次元重力分解解的注解

IF 3 4区物理与天体物理

General Relativity and Gravitation Pub Date : 2026-08-20 DOI: 10.1007/s10714-026-03588-1

Daniel Müller, Aleksey Toporensky

引用次数: 0

Evolution of density perturbations in fractional cosmology 分数宇宙学中密度微扰的演化

IF 3 4区物理与天体物理

General Relativity and Gravitation Pub Date : 2026-08-18 DOI: 10.1007/s10714-026-03600-8

S. M. M. Rasouli

{"title":"Evolution of density perturbations in fractional cosmology","authors":"S. M. M. Rasouli","doi":"10.1007/s10714-026-03600-8","DOIUrl":"10.1007/s10714-026-03600-8","url":null,"abstract":"<div><p>We investigate the evolution of matter density perturbations within a fractional cosmological framework inspired by fractal space-time constructions in field theory, where a deformation of the integration measure induces non-locality and memory effects in the dynamics. Working in the matter-dominated era and adopting a covariant fluid-flow approach, we derive the modified growth equation for the density contrast and obtain exact analytical solutions. The resulting dynamics depends explicitly on the fractional parameter <span>(alpha )</span> and smoothly reduces to the corresponding standard case in the limit <span>(alpha =1)</span>. We show that the model admits both growing and decaying modes, and we identify the parameter range in which structure formation is physically viable. Focusing on the growing mode, we compute the evolution of density fluctuations from recombination to the present epoch. By confronting theoretical predictions with observational constraints from large-scale structure, in particular the <span>(sigma _8)</span> normalization and the Sachs-Wolfe effect, we derive a stringent upper bound on the fractional parameter, <span>(alpha lesssim 1.07)</span>, which significantly improves upon previous constraints obtained at the background level. Our results show that the growth of density perturbations exhibits distinct fractional signatures, providing a sensitive observational probe of the underlying framework.</p></div>","PeriodicalId":578,"journal":{"name":"General Relativity and Gravitation","volume":"58 8","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148768963","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

The space spinor formalism and estimates for spinor fields 旋量场的空间旋量形式与估计

IF 3 4区物理与天体物理

General Relativity and Gravitation Pub Date : 2026-08-17 DOI: 10.1007/s10714-026-03579-2

Mariem Magdy, Juan A. Valiente Kroon

引用次数: 0

A simple pendulum in Schwarzschild spacetime 史瓦西时空中的单摆

IF 3 4区物理与天体物理

General Relativity and Gravitation Pub Date : 2026-08-10 DOI: 10.1007/s10714-026-03601-7

Andrzej Czarnecki, Andrew Czezowski

引用次数: 0