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Title: Comment on perturbations during a regular bounce

Abstract

We point out an inconsistency of a method used in the literature, first advocated by P. Peter and N. Pinto-Neto in [Phys. Rev. D 66, 063509 (2002)], for studying adiabatic scalar perturbations in a regular bouncing universe (in four dimensions). The method under scrutiny consists of splitting the Bardeen potential into two pieces with independent evolutions, in order to avoid a singular behavior at the boundaries of the region where the null energy condition (NEC) is violated. However, we argue that this method violates energy-momentum conservation. We then introduce a novel method which provides two independent solutions for the Bardeen potential around the boundaries, even in the case of adiabatic perturbations. The two solutions are well behaved and not divergent.

Authors:
 [1];  [2]
  1. Physics Department, Brown University, Providence, Rhode Island 02912 (United States)
  2. Department of Physics, University of Wisconsin, Madison, Wisconsin 53706 (United States)
Publication Date:
OSTI Identifier:
20776814
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. D, Particles Fields; Journal Volume: 73; Journal Issue: 4; Other Information: DOI: 10.1103/PhysRevD.73.048501; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; COSMOLOGY; DISTURBANCES; EVOLUTION; MATHEMATICAL SOLUTIONS; POTENTIALS; SCALARS; UNIVERSE

Citation Formats

Battefeld, Thorsten J., and Geshnizjani, Ghazal. Comment on perturbations during a regular bounce. United States: N. p., 2006. Web. doi:10.1103/PhysRevD.73.048501.
Battefeld, Thorsten J., & Geshnizjani, Ghazal. Comment on perturbations during a regular bounce. United States. doi:10.1103/PhysRevD.73.048501.
Battefeld, Thorsten J., and Geshnizjani, Ghazal. Wed . "Comment on perturbations during a regular bounce". United States. doi:10.1103/PhysRevD.73.048501.
@article{osti_20776814,
title = {Comment on perturbations during a regular bounce},
author = {Battefeld, Thorsten J. and Geshnizjani, Ghazal},
abstractNote = {We point out an inconsistency of a method used in the literature, first advocated by P. Peter and N. Pinto-Neto in [Phys. Rev. D 66, 063509 (2002)], for studying adiabatic scalar perturbations in a regular bouncing universe (in four dimensions). The method under scrutiny consists of splitting the Bardeen potential into two pieces with independent evolutions, in order to avoid a singular behavior at the boundaries of the region where the null energy condition (NEC) is violated. However, we argue that this method violates energy-momentum conservation. We then introduce a novel method which provides two independent solutions for the Bardeen potential around the boundaries, even in the case of adiabatic perturbations. The two solutions are well behaved and not divergent.},
doi = {10.1103/PhysRevD.73.048501},
journal = {Physical Review. D, Particles Fields},
number = 4,
volume = 73,
place = {United States},
year = {Wed Feb 15 00:00:00 EST 2006},
month = {Wed Feb 15 00:00:00 EST 2006}
}
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