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Related papers: Nonlocal star as a blackhole mimicker

200 papers

Nerd abstract: Observational constraints on spacetime are reviewed, focusing on how the underlying physics (dark matter, dark energy, gravity) can be tested rather than assumed. Popular abstract: Space is not a boring static stage on which…

Astrophysics · Physics 2017-08-23 Max Tegmark

{In (Sci. Rep. \textbf{12}, 8516 (2022)), Campos et al studied} the quasinormal modes and shadows of noncommutative Schwarzschild black holes. Since we know that the quintessence matter surrounding black holes has { significant effects} on…

General Relativity and Quantum Cosmology · Physics 2024-04-11 B. Hamil , B. C. Lütfüoğlu

It has been well known that in the point of view of a distant observer, all in-falling matter to a black hole (BH) will be eventually stalled and "frozen" just outside the event horizon of the BH, although an in-falling observer will see…

Astrophysics · Physics 2008-11-26 Shuang Nan Zhang , Yuan Liu

We propose a way to distinguish compact stellar object, whose size is very close to its Schwarzschild radius, from the collapsing stars. Namely, we show that {\it massive} fields in the vicinity of a very compact stellar object have…

General Relativity and Quantum Cosmology · Physics 2016-03-09 Emil T. Akhmedov , Daniil A. Kalinov , Fedor K. Popov

The low energy effective theory of gravity comprises two elements of quantum theory joined to classical general relativity. The first is the quantum conformal anomaly, which is responsible for macroscopic correlations on light cones and a…

General Relativity and Quantum Cosmology · Physics 2025-02-05 Emil Mottola

Thirty years of a deepening information paradox suggest the need to revise our basic physical framework. Multiple indicators point toward reassessment of the principle of locality: lack of a precise definition in quantum gravity, behavior…

High Energy Physics - Theory · Physics 2008-11-26 Steven B. Giddings

Assuming static and spherically symmetric stars with perfect fluid matter, we used realistic equations of state to study neutron stars in covariant $f(Q)$ gravity. The structure profiles and properties of neutron stars such as mass, radius…

General Relativity and Quantum Cosmology · Physics 2024-09-05 Muhammad Azzam Alwan , Tomohiro Inagaki , B. Mishra , S. A. Narawade

General properties of neutron stars are briefly reviewed with an emphasis on the indispensability of general relativity in our understanding of these fascinating objects. In Newtonian gravity the pressure within a star merely plays the role…

High Energy Astrophysical Phenomena · Physics 2017-03-02 K. Yavuz Ekşi

It is by now well established that non-relativistic matter in the Universe is dominated by dark matter, the origin and nature of which still remains a mystery. Although the collisionless dark matter paradigm works very well at large…

General Relativity and Quantum Cosmology · Physics 2019-10-28 Grigoris Panotopoulos

We perform three-dimensional, Newtonian hydrodynamic simulations with a nuclear equation of state to investigate the accretion dynamics in neutron star black hole systems. We find as a general result that non-spinning donor stars yield…

Astrophysics · Physics 2009-11-10 S. Rosswog , R. Speith , G. A. Wynn

Gravity is treated as a stochastic phenomenon based on fluctuations of the metric tensor of general relativity. By using a (3+1) slicing of spacetime, a Langevin equation for the dynamical conjugate momentum and a Fokker-Planck equation for…

General Relativity and Quantum Cosmology · Physics 2014-11-17 J. W. Moffat

The time evolution of a set of 22 Mo unstable charged stars that collapse is computed integrating the Einstein-Maxwell equations. The model simulate the collapse of an spherical star that had exhausted its nuclear fuel and have or acquires…

Astrophysics · Physics 2007-05-23 Cristian R. Ghezzi , Patricio S. Letelier

Dark stars are compact massive objects, described by Einstein gravitational field equations with matter. The type we consider possesses no event horizon, instead, there is a deep gravitational well with a very strong redshift factor.…

Astrophysics of Galaxies · Physics 2021-02-17 Igor Nikitin

We consider the sector of Horndeski's gravity characterized by the coupling between the kinetic scalar field term and the Einstein tensor. We numerically construct neutron star configurations where the external geometry is identical to the…

General Relativity and Quantum Cosmology · Physics 2015-09-02 Adolfo Cisterna , Térence Delsate , Massimiliano Rinaldi

We derive the gravitational field and the spacetime metric generated by sources in quantum superposition of different locations. We start by working in a Newtonian approximation, in which the effective gravitational potential is computed as…

General Relativity and Quantum Cosmology · Physics 2022-11-04 Ali Akil , Mariano Cadoni , Leonardo Modesto , Mauro Oi , Andrea Pierfrancesco Sanna

A new solution for the endpoint of gravitational collapse is proposed. By extending the concept of Bose-Einstein condensation to gravitational systems, a cold, compact object with an interior de Sitter condensate phase and an exterior…

General Relativity and Quantum Cosmology · Physics 2023-02-16 Pawel O. Mazur , Emil Mottola

The pseudo-complex General Relativity (pc-GR) is further considered. A new projection method is proposed. It is shown, that the pc-GR introduces automatically terms into the system which can be interpreted as dark energy. The modified…

General Relativity and Quantum Cosmology · Physics 2012-03-01 Gunther Caspar , Thomas Schönenbach , Peter Otto Hess , Mirko Schäfer , Walter Greiner

An approximate solution to Einstein's equations representing two widely-separated non-rotating black holes in a circular orbit is constructed by matching a post-Newtonian metric to two perturbed Schwarzschild metrics. The spacetime metric…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Kashif Alvi

In this chapter we present a status report of black hole-like solutions in non-local theories of gravity in which the Lagrangians are at least quadratic in curvature and contain specific non-polynomial (i.e., non-local) operators. In the…

General Relativity and Quantum Cosmology · Physics 2025-02-26 Luca Buoninfante , Breno L. Giacchini , Tibério de Paula Netto

We obtain a new, exact, solution of the Einstein's equation in higher dimensions. The source is given by a static spherically symmetric, Gaussian distribution of mass and charge. De-localization of mass and charge is due to the presence of…

High Energy Physics - Theory · Physics 2009-02-19 Euro Spallucci , Anais Smailagic , Piero Nicolini