English
Related papers

Related papers: Spherical Collapse for Viscous Generalized Chaplyg…

200 papers

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

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

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

This paper explores the cosmological implications of a scalar field with a specific potential, crucial for achieving the final equilibrium state of gravitational collapse. We consider a system with two fluids: minimally coupled matter…

General Relativity and Quantum Cosmology · Physics 2024-04-08 Koushiki , Dipanjan Dey , Pankaj S. Joshi

Length scales probed by large scale structure surveys are becoming closer to the horizon scale. Further, it has been recently understood that non-Gaussianity in the initial conditions could show up in a scale dependence of the bias of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Tobias Baldauf , Uros Seljak , Leonardo Senatore , Matias Zaldarriaga

We study structure formation in K-mouflage cosmology whose main feature is the absence of screening effect on quasilinear scales. We show that the growth of structure at the linear level is affected by both a new time dependent Newton…

Cosmology and Nongalactic Astrophysics · Physics 2014-12-02 Philippe Brax , Patrick Valageas

Using the general formalism for spherical gravitational collapse developed in [1], we investigate here the final fate of a spherical distribution of a matter cloud, where radial pressures vanish but tangential pressures are non-zero. Within…

General Relativity and Quantum Cosmology · Physics 2011-05-09 Daniele Malafarina , Pankaj S. Joshi

We investigate the gravitational collapse of a massive scalar field in a conformally flat, spherically symmetric spacetime within general relativity. The collapsing matter distribution is modeled using a minimally coupled homogeneous scalar…

General Relativity and Quantum Cosmology · Physics 2026-05-28 Mohamed Aarif A , Soumya Chakrabarti

We consider a generic type of dark energy fluid, characterised by a constant equation of state parameter w and sound speed c_s, and investigate the impact of dark energy clustering on cosmic structure formation using the spherical collapse…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Tobias Basse , Ole Eggers Bjaelde , Yvonne Y. Y. Wong

We analyse modelling techniques for the large-scale structure formed in scalar-tensor theories of constant Brans-Dicke parameter which match the concordance model background expansion history and produce a chameleon suppression of the…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-14 Lucas Lombriser , Kazuya Koyama , Baojiu Li

In the present work we study spherically symmetric gravitational collapse of a homogeneous perfect fluid in the context of Generalized Rastall Theory (GRT). In this modified version of the original {Rastall Gravity (RG)}, the coupling…

General Physics · Physics 2021-11-03 A. H. Ziaie , H. Moradpour , M. Mohammadi Sabet

The type Ia supernovae observational data are used to estimate the parameters of a cosmological model with cold dark matter and the Chaplygin gas. The Chaplygin gas model depends essentially on four parameters: the Hubble constant, the…

Astrophysics · Physics 2009-12-30 R. Colistete , J. C. Fabris , S. V. B. Gonçalves , P. E. de Souza

A particular class of space-time, with a tachyon field, \phi, and a barotropic fluid constituting the matter content, is considered herein as a model for gravitational collapse. For simplicity, the tachyon potential is assumed to be of…

General Relativity and Quantum Cosmology · Physics 2013-01-23 Yaser Tavakoli , João Marto , Amir Hadi Ziaie , Paulo Vargas Moniz

We develop a spherical self-similar model for the formation of a galaxy through gas collapsing in an isolated self-gravitating dark matter halo. We improve upon the existing literature on self-similar collapse in two ways. First, we include…

Astrophysics of Galaxies · Physics 2024-04-05 Premvijay Velmani , Aseem Paranjape

In this paper, we examine gravitational collapse of matter fields in $n$-dimensional general relativity. The matter energy-momentum tensor under consideration includes dust, perfect fluids with equations of state and matter admitting bulk…

General Relativity and Quantum Cosmology · Physics 2025-05-19 Ayan Chatterjee , Suresh C. Jaryal , Akshay Kumar

We present a scalar-field formulation of the generalized Chaplygin gas (GCG) and modified Chaplygin gas (MCG) models, in which the cosmic fluid dynamics are reproduced by canonical Lagrangians with analytically derived energy density…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-23 Yi-Syuan Wu , Chuan-Jui Li , W. F. Kao

We present the results of a set of cosmological N-body simulations with standard $\Lambda$CDM cosmology but characterized by a scale-dependent primordial non-Gaussianity of the local type featuring a power-law dependence of the $f_{\rm…

We will extend the study of the new generalized Chaplygin gas (NGCG) based on [JCAP 0601(2006)003]. Concretely, we will not only discuss the change rates of the energy densities and the energy transfer of this model, but also perform the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Wang Jun , Wu Ya-Bo , Wang Di , Yang Wei-Qiang

Understanding the formation of binary and multiple stellar systems largely comes down to studying the circumstances for the fragmentation of a condensing core during the first stages of the collapse. However, the probability of…

Solar and Stellar Astrophysics · Physics 2015-02-11 Evangelia Ntormousi , Patrick Hennebelle

A self-similar formalism for the study of the gravitational collapse of molecular gas provides an important theoretical framework from which to explore the dynamics of star formation. Motivated by the presence of elongated and filamentary…

Solar and Stellar Astrophysics · Physics 2015-05-13 Lisa Holden , Kevin Hoppins , Benjamin Baxter , Marco Fatuzzo