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Title: Two field matter bounce cosmology

Abstract

We re-examine the non-singular Matter Bounce scenario first developed in [20], which starts with a matter-dominated period of contraction and transitions into an Ekpyrotic phase of contraction. We consider both matter fields, the first of which plays the role of regular matter, and the second of which is responsible for the non-singular bounce. Since the dominant matter field is massive, the induced curvature fluctuations are initially not scale-invariant, whereas the fluctuations of the second scalar field (which are initially entropy fluctuations) are scale-invariant. We study the transfer of the initial entropy perturbations into curvature fluctuations in the matter-dominated phase of contraction and show that the latter become nearly scale invariant on large scales but are blue tilted on small scales. We study the evolution of both curvature and entropy fluctuations through the bounce, and show that both have a scale-invariant spectrum which is blue-tilted on small scales. However, we find that the entropy fluctuations have an amplitude that is much smaller than that of the curvature perturbations, due to gravitational amplification of curvature perturbations during the bounce phase.

Authors:
; ;
Publication Date:
OSTI Identifier:
22282631
Resource Type:
Journal Article
Journal Name:
Journal of Cosmology and Astroparticle Physics
Additional Journal Information:
Journal Volume: 2013; Journal Issue: 10; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1475-7516
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; AMPLIFICATION; AMPLITUDES; COSMOLOGY; ENTROPY; FLUCTUATIONS; GRAVITATION; PERTURBATION THEORY; SCALAR FIELDS; SCALE INVARIANCE

Citation Formats

Cai, Yi-Fu, McDonough, Evan, Duplessis, Francis, and Brandenberger, Robert H., E-mail: yifucai@physics.mcgill.ca, E-mail: evanmc@physics.mcgill.ca, E-mail: francis.duplessis@mail.mcgill.ca, E-mail: rhb@hep.physics.mcgill.ca. Two field matter bounce cosmology. United States: N. p., 2013. Web. doi:10.1088/1475-7516/2013/10/024.
Cai, Yi-Fu, McDonough, Evan, Duplessis, Francis, & Brandenberger, Robert H., E-mail: yifucai@physics.mcgill.ca, E-mail: evanmc@physics.mcgill.ca, E-mail: francis.duplessis@mail.mcgill.ca, E-mail: rhb@hep.physics.mcgill.ca. Two field matter bounce cosmology. United States. https://doi.org/10.1088/1475-7516/2013/10/024
Cai, Yi-Fu, McDonough, Evan, Duplessis, Francis, and Brandenberger, Robert H., E-mail: yifucai@physics.mcgill.ca, E-mail: evanmc@physics.mcgill.ca, E-mail: francis.duplessis@mail.mcgill.ca, E-mail: rhb@hep.physics.mcgill.ca. 2013. "Two field matter bounce cosmology". United States. https://doi.org/10.1088/1475-7516/2013/10/024.
@article{osti_22282631,
title = {Two field matter bounce cosmology},
author = {Cai, Yi-Fu and McDonough, Evan and Duplessis, Francis and Brandenberger, Robert H., E-mail: yifucai@physics.mcgill.ca, E-mail: evanmc@physics.mcgill.ca, E-mail: francis.duplessis@mail.mcgill.ca, E-mail: rhb@hep.physics.mcgill.ca},
abstractNote = {We re-examine the non-singular Matter Bounce scenario first developed in [20], which starts with a matter-dominated period of contraction and transitions into an Ekpyrotic phase of contraction. We consider both matter fields, the first of which plays the role of regular matter, and the second of which is responsible for the non-singular bounce. Since the dominant matter field is massive, the induced curvature fluctuations are initially not scale-invariant, whereas the fluctuations of the second scalar field (which are initially entropy fluctuations) are scale-invariant. We study the transfer of the initial entropy perturbations into curvature fluctuations in the matter-dominated phase of contraction and show that the latter become nearly scale invariant on large scales but are blue tilted on small scales. We study the evolution of both curvature and entropy fluctuations through the bounce, and show that both have a scale-invariant spectrum which is blue-tilted on small scales. However, we find that the entropy fluctuations have an amplitude that is much smaller than that of the curvature perturbations, due to gravitational amplification of curvature perturbations during the bounce phase.},
doi = {10.1088/1475-7516/2013/10/024},
url = {https://www.osti.gov/biblio/22282631}, journal = {Journal of Cosmology and Astroparticle Physics},
issn = {1475-7516},
number = 10,
volume = 2013,
place = {United States},
year = {Tue Oct 01 00:00:00 EDT 2013},
month = {Tue Oct 01 00:00:00 EDT 2013}
}