Classical and Quantum Gravity最新文献

Observations of compact stars and fermion-boson stars with a quartic self-interaction

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2025-03-31 DOI: 10.1088/1361-6382/adc361

Susana Valdez-Alvarado, Alejandro Cruz-Osorio, J M Dávila, L Arturo Ureña-López and Ricardo Becerril

引用次数: 0

Spherically symmetric collapse: initial configurations

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2025-03-31 DOI: 10.1088/1361-6382/adbf62

Elly Bayona, Hernando Quevedo and Miguel Alcubierre

引用次数: 0

Black Hole Waterfall: a unitary phenomenological model for black hole evaporation with Page curve

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2025-03-30 DOI: 10.1088/1361-6382/adc2eb

P M Alsing

{"title":"Black Hole Waterfall: a unitary phenomenological model for black hole evaporation with Page curve","authors":"P M Alsing","doi":"10.1088/1361-6382/adc2eb","DOIUrl":"https://doi.org/10.1088/1361-6382/adc2eb","url":null,"abstract":"We present a unitary phenomenological model for black hole (BH) evaporation based on the analogy of the laboratory process of spontaneous parametric down conversion (Alsing 2015 Class. Quantum Grav.32 075010; Alsing and Fanto 2016 Class. Quantum Grav.33 0150005) when the BH (pump) is allowed to deplete to zero mass. The model incorporates an additional new feature that allows for the interior Hawking partner-particles (idlers) behind the horizon to further generate new Hawking particle pairs of lower energy, one of which remains behind the horizon, and the other that adds to the externally emitted Hawking radiation (signals) outside the horizon. This model produces a Page curve for the evolution of the reduced density matrices for the evaporating BH internal degrees of freedom entangled with the generated Hawking radiation pairs entangled across the horizon. The Page curve yields an entropy that rises at early times during the evaporation process as Hawking pairs are generated, reaches a peak midway through the evolution, and then decays to zero upon complete evaporation of the BH. The entire system remains in a pure state at all times undergoing unitary (squeezed state) evolution, with the initial state of the BH modeled as a bosonic Fock state of large, but finite number of particles. For the final state of the system, the BH reaches the vacuum state of zero mass, while the external Hawking radiation carries away the total energy of the initial BH. Inside the horizon there remains Hawking partner-particles of vanishingly small total energy, reminiscent of the ‘soft-hair’ (zero energy) qubit model of Hotta et al (2018 Phys. Rev. Lett.120 181301), but now from a Hamiltonian for squeezed state generation perspective. The model presented here can be readily extended to encompass arbitrary initial pure states for the BH, and in falling matter.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"102 4 Pt 1 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143736651","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

No-hair and almost-no-hair results for static axisymmetric black holes and ultracompact objects in astrophysical environments

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2025-03-30 DOI: 10.1088/1361-6382/adc233

Carlos Barceló, Raúl Carballo-Rubio, Luis J Garay and Gerardo García-Moreno

{"title":"No-hair and almost-no-hair results for static axisymmetric black holes and ultracompact objects in astrophysical environments","authors":"Carlos Barceló, Raúl Carballo-Rubio, Luis J Garay and Gerardo García-Moreno","doi":"10.1088/1361-6382/adc233","DOIUrl":"https://doi.org/10.1088/1361-6382/adc233","url":null,"abstract":"No-hair theorems are uniqueness results constraining the form of the metric of black holes in general relativity. These theorems are typically formulated under idealized assumptions, involving a mixture of local (regularity of the horizon) and global aspects (everywhere vacuum spacetime and asymptotic flatness). This limits their applicability to astrophysical scenarios of interest such as binary black holes and accreting systems, as well as their extension to horizonless objects. A previous result due to Gürlebeck constrains the asymptotic multipolar structure of static spacetimes containing black holes surrounded by matter although not revealing the possible structure of the metric itself. In this work, we disentangle some of these assumptions in the static and axisymmetric case. Specifically: (i) we show that only a one-parameter family of black-hole geometries is compatible with a given external gravitational field, (ii) we also analyze the case in which the central object is close to forming an event horizon but is still horizonless and show that the deviations from the natural black-hole shape have to die off as one approaches the black hole limit under the physical principle that curvatures are bounded.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"29 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143736684","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

Regular Kerr black holes: junction conditions and the matter content across the ring

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2025-03-30 DOI: 10.1088/1361-6382/adbeb2

Marcos L W Basso and Vilson T Zanchin

{"title":"Regular Kerr black holes: junction conditions and the matter content across the ring","authors":"Marcos L W Basso and Vilson T Zanchin","doi":"10.1088/1361-6382/adbeb2","DOIUrl":"https://doi.org/10.1088/1361-6382/adbeb2","url":null,"abstract":"Regular rotating black holes are usually described by a metric of the Kerr–Schild form with a particular mass function that is chosen to avoid the ring singularity of the Kerr metric and which approaches the Kerr metric at the asymptotic limit. However, as is well known, even for a class of well-behaved mass functions, the curvature scalars present a discontinuity in the equatorial plane at the ring. This discontinuity has been associated with the presence of a string of matter that joins the interior and exterior regions along the equatorial plane. By using the Darmois–Israel junction conditions, we analyze all four possible combinations of the normal vector orientations on each side of the ring, construct the complete stress-energy momentum tensor of the string, and interpret each resulting solution. We show that, out of the four possibilities, only one of the four models for the string solution at the ring yields the appropriate asymptotic geometry. In such a case, the string bears a fluid with nonzero pressure, but with a vanishing line energy density, and it does not rotate at all. Finally, taking an appropriate metric for the exterior region, we also discuss a different scenario in which the matter source at the ring is a rotating lightlike fluid.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"28 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143736649","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

Analytical reconstruction of equivalent purely kinetic k-essence description for c s 2 ...

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2025-03-28 DOI: 10.1088/1361-6382/adbeb3

Dalibor Perković and Hrvoje Štefančić

引用次数: 0

Rescaled Einstein–Gauss–Bonnet gravity inflation

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2025-03-28 DOI: 10.1088/1361-6382/adc0dc

V K Oikonomou, Ardit Gkioni, Iason Sdranis, Pyotr Tsyba and Olga Razina

{"title":"Rescaled Einstein–Gauss–Bonnet gravity inflation","authors":"V K Oikonomou, Ardit Gkioni, Iason Sdranis, Pyotr Tsyba and Olga Razina","doi":"10.1088/1361-6382/adc0dc","DOIUrl":"https://doi.org/10.1088/1361-6382/adc0dc","url":null,"abstract":"We study the inflationary phenomenology of a rescaled Einstein–Gauss–Bonnet (EGB) gravity. In this framework, the gravitational constant of the Einstein–Hilbert term is rescaled due to effective terms active in the high curvature era. Basically, the total theory is an theory with the Gauss–Bonnet part contributing only a non-minimal coupling to the scalar field, so it is a theory with string theory origins and with a non-trivial F(R) gravity part. The F(R) gravity part in the high curvature regime contributes only a rescaled Einstein–Hilbert term and thus the resulting theory is effectively a rescaled version of a standard EGB theory. We develop the formalism of rescaled EGB gravity, taking in account the GW170817 constraints on the gravitational wave speed. We show explicitly how the rescaled theory affects directly the primordial scalar and tensor perturbations, and how the slow-roll and observational indices of inflation are affected by the rescaling of the theory. We perform a thorough phenomenological analysis of several models of interest and we show that is it possible to obtain viable inflationary theories compatible with the latest Planck data. Also among the studied models there are cases that yield a relatively large blue tilted tensor spectral index and we demonstrate that these models can lead to detectable primordial gravitational waves in the future gravitational wave experiments. Some of the scenarios examined, for specific values of the reheating temperature may be detectable by SKA, LISA, BBO, DECIGO and the Einstein Telescope.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"35 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143723231","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 Smarr formula within the Geroch-Held-Penrose formalism

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2025-03-28 DOI: 10.1088/1361-6382/adc180

Alberto Guilabert and Pedro Bargueño

{"title":"The Smarr formula within the Geroch-Held-Penrose formalism","authors":"Alberto Guilabert and Pedro Bargueño","doi":"10.1088/1361-6382/adc180","DOIUrl":"https://doi.org/10.1088/1361-6382/adc180","url":null,"abstract":"The connection between classical thermodynamics and black hole horizons is a fundamental topic in gravitational physics, offering a potential pathway to understanding quantum aspects of gravity. However, while black hole mechanics exhibits well-known thermodynamic parallels, a rigorous geometric interpretation of thermodynamic variables directly from the field equations warrants further research. In this manuscript, we present a thermodynamic formulation of the field equations through the decomposition of the Riemann tensor, employing the Geroch-Held-Penrose (GHP) formalism, to clarify a strong correspondence between black hole thermodynamic variables and geometrical quantities derived from horizon geometry. Our analysis reveals an intrinsic connection between the Penrose and Rindler K-curvature and the Smarr relation, motivating a revised definition of both trapping gravity and black hole internal energy. Additionally, we derive through this GHP formalism the Smarr formula for the Reissner–Nördstrom black hole cointained in an AdS spacetime and we explore the implications of this relationship for black holes with exotic topologies and in the context of extended theories, exemplified by f(R) gravity. We also briefly analyze this relation in more general configurations, such as Taub-NUT spacetimes. These findings suggest a deeper geometrical basis for black hole thermodynamics, potentially advancing our understanding of gravitational energy, horizon entropy, and their significance within quantum gravity frameworks.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"30 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143723232","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

Thermodynamics and phase transition of Bardeen–AdS-class black holes

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2025-03-27 DOI: 10.1088/1361-6382/adc232

Shan-Ping Wu and Shao-Wen Wei

{"title":"Thermodynamics and phase transition of Bardeen–AdS-class black holes","authors":"Shan-Ping Wu and Shao-Wen Wei","doi":"10.1088/1361-6382/adc232","DOIUrl":"https://doi.org/10.1088/1361-6382/adc232","url":null,"abstract":"In a generalized parameter space, regular black holes can be regarded as non-singular solutions under specific parameters in Einstein gravity theory coupled with non-linear electromagnetic fields. Following this concept, we investigate the thermodynamic states and phase transitions of Bardeen–AdS-class black holes, revealing that the system can be classified into two categories, Type I and Type II, based on whether it adopts a pure Bardeen–AdS spacetime without event horizons or a Bardeen–AdS black hole as its phase state, each exhibiting distinct thermodynamic properties. If one includes the Bardeen–AdS black holes in the system (Type I), there will be three distinct black hole states and the phase transitions between them are analogous to the Reissner–Nordstrom–AdS black holes. On the other hand, if the pure Bardeen–AdS spacetime is included (Type II), an additional tiny black hole state emerges. A phase transition reminiscent of the Hawking–Page transition was found. Significantly, in this scenario, thermodynamical characteristic curves exhibit discontinuous behavior, which attributes to the multiple horizons. The presence of a Bardeen–AdS black hole within the phase structure of the Bardeen–AdS-class black hole profoundly modifies the thermodynamical properties of the system, highlighting the novel aspects of regular black holes.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"21 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143712823","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

Information measures for fermion localization in f ( T , B ...

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2025-03-27 DOI: 10.1088/1361-6382/adc06d

Allan R P Moreira, Shi-Hai Dong and Emmanuel N Saridakis

引用次数: 0