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Related papers: Shadow of a Noncommutative Thin-Shell Gravastar

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This is a continuation and generalization of our earlier work on {\it gravastar} in (2+1) anti-de Sitter space-time to 2+1 dimensional solution of charged gravastar. Morphologically this gravastar contains three regions namely: (i) charged…

General Physics · Physics 2015-06-05 Farook Rahaman , A. A. Usmani , Saibal Ray , Safiqul Islam

Within the paradigm of non-perturbative Einstein gravity we study continuous curvature manifolds which possess de Sitter interiors and Kerr exteriors. These manifolds could represent the spacetime of rotating gravastars or other similar…

General Relativity and Quantum Cosmology · Physics 2025-03-27 Sasa Ilijic , Andrew DeBenedictis

Strong gravitational lensing from black holes results in the formation of relativistic images, in particular, relativistic Einstein rings. For objects with event horizons, the radius of the unstable light ring (photon sphere) is the lowest…

General Relativity and Quantum Cosmology · Physics 2019-05-21 Rajibul Shaikh , Pritam Banerjee , Suvankar Paul , Tapobrata Sarkar

We study the geodesic structure and observable properties of asymptotically flat regular black holes sourced by a phantom scalar field characterized by a scalar charge $A$. This parameter removes the central singularity and continuously…

General Relativity and Quantum Cosmology · Physics 2026-05-21 P. A. González , Marco Olivares , Eleftherios Papantonopoulos , Yerko Vásquez

In the context of a cubic Galileon model in which the Vainshtein mechanism suppresses the scalar field interactions with matter, we study low-density stars with slow rotation and static relativistic stars. We develop an expansion scheme to…

High Energy Physics - Theory · Physics 2014-11-07 Javier Chagoya , Kazuya Koyama , Gustavo Niz , Gianmassimo Tasinato

In this work, a generalization of the Mazur-Mottola gravastar model is explored, by considering a matching of an interior solution governed by the dark energy equation of state, $\omega\equiv p/ \rho<-1/3$, to an exterior Schwarzschild…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Francisco S. N. Lobo

In this paper, model of charged gravastar under $f(T)$ modified gravity is obtained. The model has been explored by taking the diagonal tetrad field of static spacetime together with electric charge. To solve the Einstein-Maxwell field…

General Relativity and Quantum Cosmology · Physics 2021-06-18 Piyali Bhar , Pramit Rej

Quadratic scale-invariant gravity non minimally coupled to a scalar field provides a competitive model for inflation, characterized by the transition from an unstable to a stable fixed point, both characterized by constant scalar field…

General Relativity and Quantum Cosmology · Physics 2023-01-27 Simon Boudet , Massimiliano Rinaldi , Samuele Marco Silveravalle

A new final state of gravitational collapse is proposed. By extending the concept of Bose-Einstein condensation to gravitational systems, a cold, dark, compact object with an interior de Sitter condensate $p_{_V} = -\rho_{_V}$ and an…

General Relativity and Quantum Cosmology · Physics 2009-10-19 Pawel O. Mazur , Emil Mottola

This manuscript explores the gravastar model in the $f(R,\Sigma,T)$ gravity framework, with the help of Kuchowicz metric funcition, offering an alternative to black holes. A gravastar has three regions: interior, intermediate shell, and…

General Relativity and Quantum Cosmology · Physics 2025-09-05 Bharat Singh , S. Surendra Singh

We construct gravitational atoms including self-gravity, obtaining solutions of the Einstein-Klein-Gordon equations for a scalar field surrounding a non-rotating black hole in a quasi-stationary approximation. We resolve the region near the…

General Relativity and Quantum Cosmology · Physics 2025-10-23 Miguel Alcubierre , Juan Barranco , Argelia Bernal , Juan Carlos Degollado , Alberto Diez-Tejedor , Miguel Megevand , Darío Núñez , Olivier Sarbach

The direct detection of gravitational waves opens new perspectives for measuring properties of gravitationally bound compact objects. It is then important to investigate black holes and neutron stars in alternative theories of gravity,…

General Relativity and Quantum Cosmology · Physics 2017-07-26 Javier Chagoya , Gustavo Niz , Gianmassimo Tasinato

The multipole moments and the tidal Love numbers of neutron stars and quark stars satisfy certain relations which are almost insensitive to the star's internal structure. A natural question is whether the same relations hold for different…

General Relativity and Quantum Cosmology · Physics 2017-01-24 Paolo Pani

We introduce two classes of spherically symmetric spacetimes having a thin shell of matter, in non-quadratic F(R) theories of gravity with non-constant scalar curvature R. In the first, the thin shell joins an inner region with an outer…

General Relativity and Quantum Cosmology · Physics 2020-10-07 Ernesto F. Eiroa , Griselda Figueroa-Aguirre

We attempt to study three significant tests of general relativity in higher dimensions both in commutative and non-commutative spaces. In the context of non-commutative geometry, we will consider a solution of the Einstein equation in…

General Relativity and Quantum Cosmology · Physics 2021-05-04 Davood Mahdavian Yekta , S. A. Alavi , Majid Karimabadi

Some dynamical aspects of gravitational collapse are explored in this paper. A time-dependent spherically symmetric metric is proposed and the corresponding Einstein field equations are derived. An ultrarelativistic dust-like…

General Relativity and Quantum Cosmology · Physics 2014-07-08 Miquel Pinol

We investigate the thermodynamic, optical, and dynamical properties of Reissner-Nordstrom-de Sitter black holes in a noncommutative spacetime with a minimal length scale Theta. Within a two-horizon framework, we formulate an effective first…

High Energy Physics - Theory · Physics 2026-03-24 Phongsakorn Sereewat , David Senjaya , Piyabut Burikham

We study the shadows of disformal black holes in vector-tensor Galileons modified gravity. Our analysis shows that the apparent image of the black hole in the observer's sky is non-spherical and cuspy, which is in contrast to the Kerr and…

General Relativity and Quantum Cosmology · Physics 2018-01-25 Tsvetan Vetsov , Galin Gyulchev , Stoytcho Yazadjiev

Tidal effects related to the traversability across thin shells are examined in spherically symmetric geometries. We focus mainly on shells separating inner from outer regions of gravastars (de Sitter -- i.e. $\Lambda>0$ -- interior and…

General Relativity and Quantum Cosmology · Physics 2025-03-17 Cecilia Tomasini , Claudio Simeone , Emilio Rubín de Celis

We generalize the Oppenheimer-Snyder model of gravitational collapse by considering a broader class of static, spherically symmetric exterior spacetimes, with an interior geometry described by a Friedmann-Lemaitre-Robertson-Walker (FLRW)…

General Relativity and Quantum Cosmology · Physics 2025-12-16 H. Khodabakhshi , H. Lu , F. Shojai