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Related papers: Spherical Collapse in f(R) Gravity

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We describe a non-perturbative approach to studying the gravitational collapse of a scalar field in spherical symmetry with quantum gravity corrections. Quantum effects are described by a phase space function that modifies the constraints…

General Relativity and Quantum Cosmology · Physics 2011-09-15 Andreas Kreienbuehl , Viqar Husain , Sanjeev S. Seahra

Traditionally the spherical collapse of objects is studied with respect to a uniform background density, yielding the critical over-density $\delta_\mathrm{c}$ as key ingredient to the mass function of virialized objects. Here we…

Cosmology and Nongalactic Astrophysics · Physics 2019-02-26 Robert Reischke , Francesco Pace , Sven Meyer , Björn Malte Schäfer

We study the gravitational collapse in modified gravitational theories. In particular, we analyze a general $f(R)$ model with uniformly collapsing cloud of self-gravitating dust particles. This analysis shares analogies with the formation…

General Relativity and Quantum Cosmology · Physics 2015-06-03 J. A. R. Cembranos , A. de la Cruz-Dombriz , B. Montes Nuñez

We study the spherical collapse model in the presence of external gravitational tidal shear fields for different dark energy scenarios and investigate the impact on the mass function and cluster number counts. While previous studies of the…

Cosmology and Nongalactic Astrophysics · Physics 2016-12-12 Robert Reischke , Francesco Pace , Sven Meyer , Björn Malte Schäfer

Spherical vacuum and scalar collapse for the Starobinsky R^2 model is simulated. Obtained by considering the quantum-gravitational effects, this model would admit some cases of singularity-free cosmological spacetimes. It is found, however,…

General Relativity and Quantum Cosmology · Physics 2016-09-01 Jun-Qi Guo , Pankaj S. Joshi

We generalize the spherical collapse model for the formation of dark matter halos 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 2016-11-03 Ewa L. Lokas , Y. Hoffman

We give a review of recent work aimed at understanding the dynamics of gravitational collapse in quantum gravity. Its goal is to provide a non-perturbative computational framework for understanding the emergence of the semi-classical…

General Relativity and Quantum Cosmology · Physics 2008-01-09 Viqar Husain

We investigate a spherical collapse model with and without the spatial curvature. We obtain the exact solutions of dynamical quantities such as the ratio of the scale factor to its value at the turnaround epoch and the ratio of the…

Cosmology and Nongalactic Astrophysics · Physics 2010-03-29 Seokcheon Lee

We refine the mass and environment dependent spherical collapse model of chameleon $f(R)$ gravity by calibrating a phenomenological correction inspired by the parameterized post-Friedmann framework against high-resolution $N$-body…

Cosmology and Nongalactic Astrophysics · Physics 2017-04-12 Matteo Cataneo , David Rapetti , Lucas Lombriser , Baojiu Li

Gravitational collapse into a black hole has been extensively studied with classical sources. We develop a new formalism to simulate quantum fields forming a black hole. This formalism utilizes well-established techniques used for classical…

General Relativity and Quantum Cosmology · Physics 2021-08-18 Benjamin Berczi , Paul M. Saffin , Shuang-Yong Zhou

Examining the relativistic collapse of a spherical spacetime where gravity is coupled with a scalar field, this review provides a thorough analysis of some of the most relevant studies from both analytical and numerical perspectives. The…

General Relativity and Quantum Cosmology · Physics 2024-05-09 Roberto Giambò

We study critical phenomena in the gravitational collapse of a radiation fluid. We perform numerical simulations in both spherical symmetry and axisymmetry, and observe critical scaling in both supercritical evolutions, which lead to the…

General Relativity and Quantum Cosmology · Physics 2016-01-08 Thomas W. Baumgarte , Pedro J. Montero

We consider the problem of critical gravitational collapse of a scalar field in 2+1 dimensions with spherical (circular) symmetry. After surveying all the analytic, continuously self-similar solutions and considering their global structure,…

General Relativity and Quantum Cosmology · Physics 2009-07-07 Eric W. Hirschmann , Anzhong Wang , Yumei Wu

Numerical simulations are performed of a test scalar field in a spacetime undergoing gravitational collapse. The behavior of the scalar field near the singularity is examined and implications for generic singularities are discussed. In…

General Relativity and Quantum Cosmology · Physics 2011-09-12 Ryo Saotome , Ratindranath Akhoury , David Garfinkle

Gravitational collapse of a class of spherically symmetric stars are investigated. We quantise the geometries describing the gravitational collapse by a deformation quantisation procedure. This gives rise to noncommutative spacetimes with…

High Energy Physics - Theory · Physics 2011-02-09 Wen Sun , Ding Wang , Naqing Xie , R. B. Zhang , Xiao Zhang

It is known that radial collapse around density peaks can explain the key features of evolution of correlation function in gravitational clustering in three dimensions. The same model also makes specific predictions for two dimensions. In…

Astrophysics · Physics 2009-10-30 J. S. Bagla , S. Engineer , T. Padmanabhan

We study gravitational collapse for the Starobinsky $R^2$ model, a particular example of an $f(r)$ theory, in a spherically symmetric spacetime. We add a massless scalar field as matter content to the spacetime. We work in the Einstein…

General Relativity and Quantum Cosmology · Physics 2023-01-02 Yolbeiker Rodríguez Baez

We study the dynamics of the critical collapse of a spherically symmetric scalar field. Approximate analytic expressions for the metric functions and matter field in the large-radius region are obtained. In the central region, owing to the…

General Relativity and Quantum Cosmology · Physics 2024-05-13 Jun-Qi Guo , Yu Hu , Pan-Pan Wang , Cheng-Gang Shao

We study spherical collapse in the Quartic and Quintic Covariant Galileon gravity models within the framework of the excursion set formalism. We derive the nonlinear spherically symmetric equations in the quasi-static and weak-field limits,…

Cosmology and Nongalactic Astrophysics · Physics 2014-04-24 Alexandre Barreira , Baojiu Li , Carlton Baugh , Silvia Pascoli

In this paper we study an Oppenheimer-Snyder (OS)-like gravitational collapse in the general framework of scale-dependent gravity. We explore the collapse in spherically symmetric solutions suggested both by asymptotically safe gravity…

General Relativity and Quantum Cosmology · Physics 2025-04-07 Ramin Hassannejad , Gaetano Lambiase , Fabio Scardigli , Fatimah Shojai