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Non-Singular Gravitational Collapse of a Homogeneous Scalar Field in Deformed Phase Space
Authors: Amir Hadi Ziaie
Abstract:In the present work, we revisit the collapse process of a spherically symmetric homogeneous scalar field (in FRW background) minimally coupled to gravity, when the phase-space deformations are taken into account. Such a deformation is mathematically introduced as a particular type of noncommutativity between the canonical momenta of the scale factor and of the scalar field. In the absence of such deformation, the collapse culminates in a spacetime singularity. However, when the phase-space is deformed, we find that the singularity is removed by a non-singular bounce, beyond which the collapsing cloud re-expands to infinity. More precisely, for negative values of the deformation parameter, we identify the appearance of a negative pressure, which decelerates the collapse to finally avoid the singularity formation. While in the un-deformed case, the horizon curve monotonically decreases to finally cover the singularity, in the deformed case the horizon has a minimum value that this value depends on deformation parameter and initial configuration of the collapse. Such a setting predicts a threshold mass for black hole formation in stellar collapse and manifests the role of non-commutative geometry in physics and especially in stellar collapse and supernova explosion.
Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1125889Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 955
 Pankaj S. Joshi, “Gravitational collapse and spacetime singularities” Cambridge University Press (2007).
 H. S. Snyder, Phys. Rev 71 38 (1947); Phys. Rev 72 68 (1947).
 T. Banks, W. Fischler, S. H. Shenker and L. Susskind, Phys. Rev. D 55 5112 (1997).
 E. Di Grezia, G. Esposito, G. Miele, J. Phys. A 41 164063 (2008)
 S. M. M. Rasouli, A. H. Ziaie, J. Marto, P. V. Moniz, Phys. Rev. D 89, 044028 (2014).
 S. M. M. Rasouli, M. Farhoudi and N. Khosravi, Gen. Relativ. Gravit. 43 2895 (2011).
 N. Khosravi, H. R. Sepangi and M. M. Sheikh-Jabbari, Phys. Lett. B 647 219 (2007).