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Related papers: Spherical Collapse in Modified Gravity Theories

200 papers

We analyze the Scherk-Schwarz (SS) supersymmetry breaking in brane-world five dimensional theories compactified on the orbifold $S^1/\mathbb{Z}_2$. The SS breaking parameter is undetermined at the tree-level (no-scale supergravity) and can…

High Energy Physics - Theory · Physics 2010-11-19 G. v. Gersdorff , M. Quiros , A. Riotto

In this work, we consider a semiclassical description of the spherically symmetric gravitational collapse with a massless scalar field. In particular, we employ an effective scenario provided by holonomy corrections from loop quantum…

General Relativity and Quantum Cosmology · Physics 2014-05-21 Yaser Tavakoli , Joao Marto , Andrea Dapor

This paper is devoted to study the gravitational charged perfect fluid collapse in the Friedmann universe models with cosmological constant. For this purpose, we assume that the electromagnetic field is so weak that it does not introduce…

General Relativity and Quantum Cosmology · Physics 2015-05-18 M. Sharif , G. Abbas

We generalize the spherical collapse model for the formation of bound objects to apply in a Universe with arbitrary positive cosmological constant. We calculate the critical condition for collapse of an overdense region and give exact…

Astrophysics · Physics 2007-05-23 Ewa L. Lokas , Yehuda Hoffman

We investigate the collapse of a spherical shell of matter in an anti-de Sitter space. We search for a holographic description of the collapsing shell in the boundary theory. It turns out that in the boundary theory it is possible to find…

High Energy Physics - Theory · Physics 2010-11-19 Ulf H. Danielsson , Esko Keski-Vakkuri , Martin Kruczenski

This study explores the link between Modified Gravity and modifications of phase space volume. Analyzing Fermi gas modifications {in the non-relativistic limit of the} Ricci-based gravities, we derive a generalized partition function in the…

General Relativity and Quantum Cosmology · Physics 2024-01-10 Aneta Wojnar

A generalized geometric method is developed for constructing exact solutions of gravitational field equations in Einstein theory and generalizations. First, we apply the formalism of nonholonomic frame deformations (formally considered for…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Sergiu I. Vacaru

We study the parameterized post-Newtonian approximation in teleparallel model of gravity with a scalar field. The scalar field is non-minimally coupled to the scalar torsion as well as to the boundary term introduced in [1]. We show that,…

General Relativity and Quantum Cosmology · Physics 2017-04-06 H. Mohseni Sadjadi

We present a detailed study of the spherically symmetric solutions in Lorentz breaking massive gravity. There is an undetermined function $\mathcal{F}(X, w_1, w_2, w_3)$ in the action of St\"{u}ckelberg fields…

General Relativity and Quantum Cosmology · Physics 2016-04-29 Ping Li , Xin-zhou Li , Ping Xi

The relativistic motion of a compact binary system moving in circular orbit is investigated using the post-Newtonian (PN) approximation and the perturbative self-force (SF) formalism. A particular gauge-invariant observable quantity is…

General Relativity and Quantum Cosmology · Physics 2015-05-19 Luc Blanchet , Steven Detweiler , Alexandre Le Tiec , Bernard F. Whiting

The basic strategy underlying models of spontaneous wave function collapse (collapse models) is to modify the Schroedinger equation by including nonlinear stochastic terms, which tend to localize wave functions in space in a dynamical…

Quantum Physics · Physics 2015-06-18 A. Bassi , H. Ulbricht

We analyze some relevant semiclassical and quantum features of the implementation of Polymer Quantum Mechanics to the phenomenology of the flat isotropic Universe. We firstly investigate a parallelism between the semiclassical polymer…

General Relativity and Quantum Cosmology · Physics 2020-04-17 Gabriele Barca , Paolo Di Antonio , Giovanni Montani , Alberto Patti

We study how the presence of an area gap, different than zero, affects the gravitational collapse of a dust ball. The implementation of such discreteness is achieved through the framework of polymer quantization, a scheme inspired by loop…

General Relativity and Quantum Cosmology · Physics 2025-05-13 L. Boldorini , G. Montani

We study the spherical collapse of non-top-hat matter fluctuations in the presence of dark energy with arbitrary sound speed. The model is described by a system of partial differential equations solved using a pseudo-spectral method with…

Cosmology and Nongalactic Astrophysics · Physics 2023-02-22 R. C. Batista , H. P. de Oliveira , L. R. W. Abramo

We provide a general algorithm to construct a Hamiltonian, such that its dynamical flow covariantly defines any given spherically symmetric and static metric. This Hamiltonian is defined as a linear combination of the standard (general…

General Relativity and Quantum Cosmology · Physics 2025-11-21 Asier Alonso-Bardaji , David Brizuela

In this work we introduced a new proposal to study the gravitational lensing theory by spherical lenses, starting from its surface mass density $\Sigma(x)$ written in terms of a decreasing function $f$ of a dimensionless coordinate $x$ on…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-21 Roger Hurtado , Leonardo Castaneda , Juan M. Tejeiro

The Press-Schechter theory of the cosmological mass function and its modifications allow to constraint cosmological scenarios of the structure formation. Recently a few new models have been suggested that explored the influence of…

Astrophysics · Physics 2015-06-24 Sergei F. Shandarin

In this work we study the spherical symmetric solutions of $f(R)$ gravity in the metric formalism. We show that for a generic $f(R)$ gravity, the spherical symmetric solution is consistent with the modified gravity equations except in the…

Astrophysics · Physics 2015-05-13 Reza Saffari , Sohrab Rahvar

In this review we present a thoroughly comprehensive survey of recent work on modified theories of gravity and their cosmological consequences. Amongst other things, we cover General Relativity, Scalar-Tensor, Einstein-Aether, and Bimetric…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Timothy Clifton , Pedro G. Ferreira , Antonio Padilla , Constantinos Skordis

In this paper, we propose a reduced-dimensional smoothed particle hydrodynamics (SPH) formulation for quasi-static and dynamic analyses of plate and shell structures undergoing finite deformation and large rotation. By exploiting…

Numerical Analysis · Mathematics 2023-09-07 Dong Wu , Chi Zhang , Xiangyu Hu