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Title: Non-singular Brans–Dicke collapse in deformed phase space

Abstract

We study the collapse process of a homogeneous perfect fluid (in FLRW background) with a barotropic equation of state in Brans–Dicke (BD) theory in the presence of phase space deformation effects. Such a deformation is introduced as a particular type of non-commutativity between phase space coordinates. For the commutative case, it has been shown in the literature (Scheel, 1995), that the dust collapse in BD theory leads to the formation of a spacetime singularity which is covered by an event horizon. In comparison to general relativity (GR), the authors concluded that the final state of black holes in BD theory is identical to the GR case but differs from GR during the dynamical evolution of the collapse process. However, the presence of non-commutative effects influences the dynamics of the collapse scenario and consequently a non-singular evolution is developed in the sense that a bounce emerges at a minimum radius, after which an expanding phase begins. Such a behavior is observed for positive values of the BD coupling parameter. For large positive values of the BD coupling parameter, when non-commutative effects are present, the dynamics of collapse process differs from the GR case. Finally, we show that for negative values ofmore » the BD coupling parameter, the singularity is replaced by an oscillatory bounce occurring at a finite time, with the frequency of oscillation and amplitude being damped at late times.« less

Authors:
 [1]
  1. Departamento de Física, Universidade da Beira Interior, Rua Marquês d’Avila e Bolama, 6200 Covilhã (Portugal)
Publication Date:
OSTI Identifier:
22617433
Resource Type:
Journal Article
Journal Name:
Annals of Physics
Additional Journal Information:
Journal Volume: 375; Other Information: Copyright (c) 2016 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0003-4916
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; BLACK HOLES; EQUATIONS OF STATE; GENERAL RELATIVITY THEORY; GRAVITATIONAL COLLAPSE; IDEAL FLOW; PHASE SPACE; SINGULARITY; SPACE-TIME

Citation Formats

Rasouli, S. M.M.,, Centro de Matemática e Aplicações, Physics Group, Qazvin Branch, Islamic Azad University, Qazvin, Ziaie, A.H., E-mail: ah_ziaie@sbu.ac.ir, Department of Physics, Shahid Bahonar University, PO Box 76175, Kerman, Jalalzadeh, S., E-mail: shahram.jalalzadeh@unila.edu.br, Moniz, P.V., E-mail: pmoniz@ubi.pt, and Centro de Matemática e Aplicações. Non-singular Brans–Dicke collapse in deformed phase space. United States: N. p., 2016. Web. doi:10.1016/J.AOP.2016.09.007.
Rasouli, S. M.M.,, Centro de Matemática e Aplicações, Physics Group, Qazvin Branch, Islamic Azad University, Qazvin, Ziaie, A.H., E-mail: ah_ziaie@sbu.ac.ir, Department of Physics, Shahid Bahonar University, PO Box 76175, Kerman, Jalalzadeh, S., E-mail: shahram.jalalzadeh@unila.edu.br, Moniz, P.V., E-mail: pmoniz@ubi.pt, & Centro de Matemática e Aplicações. Non-singular Brans–Dicke collapse in deformed phase space. United States. https://doi.org/10.1016/J.AOP.2016.09.007
Rasouli, S. M.M.,, Centro de Matemática e Aplicações, Physics Group, Qazvin Branch, Islamic Azad University, Qazvin, Ziaie, A.H., E-mail: ah_ziaie@sbu.ac.ir, Department of Physics, Shahid Bahonar University, PO Box 76175, Kerman, Jalalzadeh, S., E-mail: shahram.jalalzadeh@unila.edu.br, Moniz, P.V., E-mail: pmoniz@ubi.pt, and Centro de Matemática e Aplicações. 2016. "Non-singular Brans–Dicke collapse in deformed phase space". United States. https://doi.org/10.1016/J.AOP.2016.09.007.
@article{osti_22617433,
title = {Non-singular Brans–Dicke collapse in deformed phase space},
author = {Rasouli, S. M.M., and Centro de Matemática e Aplicações and Physics Group, Qazvin Branch, Islamic Azad University, Qazvin and Ziaie, A.H., E-mail: ah_ziaie@sbu.ac.ir and Department of Physics, Shahid Bahonar University, PO Box 76175, Kerman and Jalalzadeh, S., E-mail: shahram.jalalzadeh@unila.edu.br and Moniz, P.V., E-mail: pmoniz@ubi.pt and Centro de Matemática e Aplicações},
abstractNote = {We study the collapse process of a homogeneous perfect fluid (in FLRW background) with a barotropic equation of state in Brans–Dicke (BD) theory in the presence of phase space deformation effects. Such a deformation is introduced as a particular type of non-commutativity between phase space coordinates. For the commutative case, it has been shown in the literature (Scheel, 1995), that the dust collapse in BD theory leads to the formation of a spacetime singularity which is covered by an event horizon. In comparison to general relativity (GR), the authors concluded that the final state of black holes in BD theory is identical to the GR case but differs from GR during the dynamical evolution of the collapse process. However, the presence of non-commutative effects influences the dynamics of the collapse scenario and consequently a non-singular evolution is developed in the sense that a bounce emerges at a minimum radius, after which an expanding phase begins. Such a behavior is observed for positive values of the BD coupling parameter. For large positive values of the BD coupling parameter, when non-commutative effects are present, the dynamics of collapse process differs from the GR case. Finally, we show that for negative values of the BD coupling parameter, the singularity is replaced by an oscillatory bounce occurring at a finite time, with the frequency of oscillation and amplitude being damped at late times.},
doi = {10.1016/J.AOP.2016.09.007},
url = {https://www.osti.gov/biblio/22617433}, journal = {Annals of Physics},
issn = {0003-4916},
number = ,
volume = 375,
place = {United States},
year = {Thu Dec 15 00:00:00 EST 2016},
month = {Thu Dec 15 00:00:00 EST 2016}
}