发布求助
文献互助 智能选刊 最新文献

arXiv: General Relativity and Quantum Cosmology最新文献

筛选
英文 中文
Photon surfaces in less symmetric spacetimes 不对称时空中的光子表面
arXiv: General Relativity and Quantum Cosmology Pub Date : 2020-11-20 DOI: 10.1103/PHYSREVD.103.044003
Yasutaka Koga, Takahisa Igata, Keisuke Nakashi
{"title":"Photon surfaces in less symmetric spacetimes","authors":"Yasutaka Koga, Takahisa Igata, Keisuke Nakashi","doi":"10.1103/PHYSREVD.103.044003","DOIUrl":"https://doi.org/10.1103/PHYSREVD.103.044003","url":null,"abstract":"We investigate photon surfaces and their stability in a less symmetric spacetime, a general static warped product with a warping function acting on a Riemannian submanifold of codimension two. We find a one-dimensional pseudopotential that gives photon surfaces as its extrema regardless of the spatial symmetry of the submanifold. The maxima and minima correspond to unstable and stable photon surfaces, respectively. It is analogous to the potential giving null circular orbits in a spherically symmetric spacetime. We also see that photon surfaces indeed exist for the spacetimes which are solutions to the Einstein equation. The parameter values for which the photon surfaces exist are specified. As we show finally, the pseudopotential arises due to the separability of the null geodesic equation, and the separability comes from the existence of a Killing tensor in the spacetime. The result leads to the conclusion that photon surfaces may exist even in a less symmetric spacetime if the spacetime admits a Killing tensor.","PeriodicalId":8455,"journal":{"name":"arXiv: General Relativity and Quantum Cosmology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88930175","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 9
Unruh-DeWitt detector differentiation of black holes and exotic compact objects Unruh-DeWitt探测器对黑洞和奇异致密物体的区分
arXiv: General Relativity and Quantum Cosmology Pub Date : 2020-11-20 DOI: 10.1103/PhysRevD.103.124046
B. Holdom, R. Mann, Chen Zhang
{"title":"Unruh-DeWitt detector differentiation of black holes and exotic compact objects","authors":"B. Holdom, R. Mann, Chen Zhang","doi":"10.1103/PhysRevD.103.124046","DOIUrl":"https://doi.org/10.1103/PhysRevD.103.124046","url":null,"abstract":"We study the response of a static Unruh-DeWitt detector outside an exotic compact object (ECO) with a general reflective boundary condition in 3+1 dimensions. The horizonless ECO, whose boundary is extremely close to the would-be event horizon, acts as a black hole mimicker. We find that the response rate is notably distinct from the black hole case, even when the ECO boundary is perfectly absorbing. For a (partially) reflective ECO boundary, we find resonance structures in the response rate that depend on the different locations of the ECO boundary and those of the detector. We provide a detailed analysis in connection with the ECO's vacuum mode structure and transfer function.","PeriodicalId":8455,"journal":{"name":"arXiv: General Relativity and Quantum Cosmology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80403335","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 2
Toward Nonlocal Electrodynamics of Accelerated Systems 加速系统的非局部电动力学研究
arXiv: General Relativity and Quantum Cosmology Pub Date : 2020-11-18 DOI: 10.3390/universe6120229
B. Mashhoon
{"title":"Toward Nonlocal Electrodynamics of Accelerated Systems","authors":"B. Mashhoon","doi":"10.3390/universe6120229","DOIUrl":"https://doi.org/10.3390/universe6120229","url":null,"abstract":"We revisit acceleration-induced nonlocal electrodynamics and the phenomenon of photon spin-rotation coupling. The kernel of the theory for the electromagnetic field tensor involves parity violation under the assumption of linearity of the field kernel in the acceleration tensor. However, we show that parity conservation can be maintained by extending the field kernel to include quadratic terms in the acceleration tensor. The field kernel must vanish in the absence of acceleration; otherwise, a general dependence of the kernel on the acceleration tensor cannot be theoretically excluded. The physical implications of the quadratic kernel are briefly discussed.","PeriodicalId":8455,"journal":{"name":"arXiv: General Relativity and Quantum Cosmology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90056852","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 3
Thermodynamic aspects of entropic cosmology with viscosity 具有粘性的熵宇宙学的热力学方面
arXiv: General Relativity and Quantum Cosmology Pub Date : 2020-11-18 DOI: 10.1142/s0218271821500085
I. Brevik, A. Timoshkin, A. Timoshkin
{"title":"Thermodynamic aspects of entropic cosmology with viscosity","authors":"I. Brevik, A. Timoshkin, A. Timoshkin","doi":"10.1142/s0218271821500085","DOIUrl":"https://doi.org/10.1142/s0218271821500085","url":null,"abstract":"We describe the evolution of the early and late universe from thermodynamic considerations, using the generalized non-extensive Tsallis entropy with a variable exponent. A new element in our analysis is the inclusion of a bulk viscosity in the description of the cosmic fluid. Using the generalized Friedmann equation, a description of the early and the late universe is obtained.","PeriodicalId":8455,"journal":{"name":"arXiv: General Relativity and Quantum Cosmology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79752661","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 6
A study on causality in f(R,ϕ,X) theory f(R， φ，X)理论中因果关系的研究
arXiv: General Relativity and Quantum Cosmology Pub Date : 2020-11-16 DOI: 10.1142/S0217751X21500093
J. Gonccalves, A. F. Santos
{"title":"A study on causality in f(R,ϕ,X) theory","authors":"J. Gonccalves, A. F. Santos","doi":"10.1142/S0217751X21500093","DOIUrl":"https://doi.org/10.1142/S0217751X21500093","url":null,"abstract":"The $k$-essence modified $f(R)$ gravity model, i.e., $f(R,phi,X)$ theory is studied. The question of violation of causality, in the framework of Godel-type universes, is investigated in this gravitational model. Causal and non-causal solutions are allowed. A critical radius for non-causal solution is calculated. It is shown that the violation of causality depends on the content of matter.","PeriodicalId":8455,"journal":{"name":"arXiv: General Relativity and Quantum Cosmology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88449737","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 2
Scalar perturbations of black holes in Jackiw-Teitelboim gravity Jackiw-Teitelboim引力中黑洞的标量微扰
arXiv: General Relativity and Quantum Cosmology Pub Date : 2020-11-14 DOI: 10.1103/physrevd.103.024008
Srijit Bhattacharjee, Subhodeep Sarkar, Arpan Bhattacharyya
{"title":"Scalar perturbations of black holes in Jackiw-Teitelboim gravity","authors":"Srijit Bhattacharjee, Subhodeep Sarkar, Arpan Bhattacharyya","doi":"10.1103/physrevd.103.024008","DOIUrl":"https://doi.org/10.1103/physrevd.103.024008","url":null,"abstract":"We study linear scalar perturbations of black holes in two space-time dimensional (2D) gravity models with particular emphasis on Jackiw-Teitelboim (JT) gravity. We obtain an exact expression for the quasinormal mode frequencies for single horizon JT black holes and then verify it numerically using the Horowitz-Hubeny method. For a 2D Reissner-Nordstr\"om like solution, we find that the scalar wave equation reduces to the confluent Heun equation using which we calculate the quasi-frequencies. Finally, we consider the dimensionally reduced BTZ black hole and obtain the exterior and interior quasinormal modes. The dynamics of a scalar field near the Cauchy horizon mimics the behaviour of the same for the BTZ black hole, indicating a possible violation of strong cosmic censorship conjecture in near extreme limit. However, quantum effects seem to rescue strong cosmic censorship.","PeriodicalId":8455,"journal":{"name":"arXiv: General Relativity and Quantum Cosmology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88002539","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 10
What is a reduced boundary in general relativity? 广义相对论中的简化边界是什么?
arXiv: General Relativity and Quantum Cosmology Pub Date : 2020-11-14 DOI: 10.1142/S0218271821500504
E. Battista, G. Esposito
{"title":"What is a reduced boundary in general relativity?","authors":"E. Battista, G. Esposito","doi":"10.1142/S0218271821500504","DOIUrl":"https://doi.org/10.1142/S0218271821500504","url":null,"abstract":"The concept of boundary plays an important role in several branches of general relativity, e.g., the variational principle for the Einstein equations, the event horizon and the apparent horizon of black holes, the formation of trapped surfaces. On the other hand, in a branch of mathematics known as geometric measure theory, the usefulness has been discovered long ago of yet another concept, i.e., the reduced boundary of a finite-perimeter set. This paper proposes therefore a definition of finite-perimeter sets and their reduced in general relativity. Moreover, a basic integral formula of geometric measure theory is evaluated explicitly in the relevant case of Euclidean Schwarzschild geometry, for the first time in the literature. This research prepares the ground for a measure-theoretic approach to several concepts in gravitational physics, supplemented by geometric insight. Moreover, such an investigation suggests considering the possibility that the in-out amplitude for Euclidean quantum gravity should be evaluated over finite-perimeter Riemannian geometries that match the assigned data on their reduced boundary.","PeriodicalId":8455,"journal":{"name":"arXiv: General Relativity and Quantum Cosmology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84047101","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 3
Remarks on the Abraham–Minkowski problem, from the formal and from the experimental side 论亚伯拉罕-闵可夫斯基问题，从形式和实验两方面
arXiv: General Relativity and Quantum Cosmology Pub Date : 2020-11-13 DOI: 10.1142/S0217751X21500639
I. Brevik, M. Chaichian, Ion I. Cotùaescu
{"title":"Remarks on the Abraham–Minkowski problem, from the formal and from the experimental side","authors":"I. Brevik, M. Chaichian, Ion I. Cotùaescu","doi":"10.1142/S0217751X21500639","DOIUrl":"https://doi.org/10.1142/S0217751X21500639","url":null,"abstract":"We analyze the Abraham-Minkowski problem known from classical electrodynamics from two different perspectives. First, we follow a formal approach, implying use of manifolds with curved space sections in accordance with Fermat's principle, emphasizing that the resulting covariant and contravariant components of the photon four-momentum is a property linked to the {it Minkowski} theory only. There is thus no link to the Abraham theory in that context. Next we turn to the experimental side, giving a brief account of older and newer radiation pressure experiments that clearly show how the Minkowski photon momentum is preferable under optical conditions. Under low-frequency conditions, where experimental detection of the individual oscillations predicted by the Abraham term are possible, the picture is however quite different.","PeriodicalId":8455,"journal":{"name":"arXiv: General Relativity and Quantum Cosmology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90495658","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
Constraining velocity-dependent Lorentz and CPT violations using lunar laser ranging 利用月球激光测距约束速度依赖的洛伦兹和CPT违规
arXiv: General Relativity and Quantum Cosmology Pub Date : 2020-11-12 DOI: 10.1103/PHYSREVD.103.064055
A. Bourgoin, S. Bouquillon, Aurélien Hees, C. L. Poncin-Lafitte, Quentin G. Bailey, J. J. Howard, M. Angonin, G. Francou, Julien Chabé, Clément Courde, J.-M. Torre
{"title":"Constraining velocity-dependent Lorentz and \u0000CPT\u0000 violations using lunar laser ranging","authors":"A. Bourgoin, S. Bouquillon, Aurélien Hees, C. L. Poncin-Lafitte, Quentin G. Bailey, J. J. Howard, M. Angonin, G. Francou, Julien Chabé, Clément Courde, J.-M. Torre","doi":"10.1103/PHYSREVD.103.064055","DOIUrl":"https://doi.org/10.1103/PHYSREVD.103.064055","url":null,"abstract":"The possibility for Lorentz/CPT-breaking, which is motivated by unification theories, can be systematically tested within the standard-model extension framework. In the pure gravity sector, the mass dimension 5 operators produce new Lorentz and CPT-breaking terms in the 2-body equations of motion that depend on the relative velocity of the bodies. In this Letter, we report new constraints on 15 independent SME coefficients for Lorentz/CPT-violations with mass dimension 5 using lunar laser ranging. We perform a global analysis of lunar ranging data within the SME framework using more than 26,000 normal points between 1969 and 2018. We also perform a jackknife analysis in order to provide realistic estimates of the systematic uncertainties. No deviation from Lorentz/CPT symmetries is reported. In addition, when fitting simultaneously for the 15 canonical SME coefficients for Lorentz/CPT-violations, we improve up to three orders of magnitude previous post-fit constraints from radio pulsars.","PeriodicalId":8455,"journal":{"name":"arXiv: General Relativity and Quantum Cosmology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87488399","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 6
Dynamics of test particles around a Bardeen black hole surrounded by perfect fluid dark matter 被完美流体暗物质包围的巴丁黑洞周围测试粒子的动力学
arXiv: General Relativity and Quantum Cosmology Pub Date : 2020-11-12 DOI: 10.1103/PhysRevD.102.104062
Bakhtiyor Narzilloev, J. Rayimbaev, S. Shaymatov, A. Abdujabbarov, B. Ahmedov, C. Bambi
{"title":"Dynamics of test particles around a Bardeen black hole surrounded by perfect fluid dark matter","authors":"Bakhtiyor Narzilloev, J. Rayimbaev, S. Shaymatov, A. Abdujabbarov, B. Ahmedov, C. Bambi","doi":"10.1103/PhysRevD.102.104062","DOIUrl":"https://doi.org/10.1103/PhysRevD.102.104062","url":null,"abstract":"We study the dynamics of (i) neutral test particles, (ii) magnetically charged test particles, and (iii) test magnetic dipole around a regular Bardeen black hole surrounded by perfect fluid dark matter (PFDM). It has been shown how the magnetic charge of the black hole and the parameter of the surrounding PFDM can influence the innermost stable circular orbit (ISCO) radius of a test particle. We have found that the ISCO radius is strongly affected as a consequence of the combined effect of the magnetic charge parameter and the perfect fluid dark matter. The black hole magnetic charge parameter $g$ and the combined effect of perfect fluid dark matter can mimic the black hole rotation parameter up to $a/Mapprox 0.9$. It has been observed that the ISCO for magnetic dipole disappears at the values exceeding the calculated upper value for the magnetic interaction parameter $beta$. The upper limit decreases with the increase of both the dark matter and magnetic charge parameters. Finally, as an astrophysical application, we have analyzed degeneracy effects of spin of Kerr black holes and magnetic charge of regular Bardeen black holes for the different values of the dark matter parameter providing exactly the same value for ISCO radius of a magnetic dipole with the same value of the parameter $beta=10.2$ of the magnetar called PSR J1745-2900 orbiting around supermassive black hole Sagittarius A*.","PeriodicalId":8455,"journal":{"name":"arXiv: General Relativity and Quantum Cosmology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79768793","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 16
首页 上一页 下一页 尾页
0
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整，为了账户安全，请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
现在去查看 取消
×
提示
确定
请完成安全验证×
相关产品
×
本文献相关产品
联系我们：info@booksci.cn Book学术提供免费学术资源搜索服务，方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号：481959085
Book学术官方微信