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Title: Cosmological dynamics of a Dirac-Born-Infeld field

Abstract

We analyze the dynamics of a Dirac-Born-Infeld (DBI) field in a cosmological setup which includes a perfect fluid. Introducing convenient dynamical variables, we show that the evolution equations form an autonomous system when the potential and the brane tension of the DBI field are arbitrary power law or exponential functions of the DBI field. In particular we find scaling solutions can exist when powers of the field in the potential and warp factor satisfy specific relations. A new class of fixed-point solutions are obtained corresponding to points which initially appear singular in the evolution equations, but on closer inspection are actually well defined. In all cases, we perform a phase-space analysis and obtain the late-time attractor structure of the system. Of particular note when considering cosmological perturbations in DBI inflation is a fixed-point solution where the Lorentz factor is a finite large constant and the equation of state parameter of the DBI field is w=-1. Since in this case the speed of sound c{sub s} becomes constant, the solution can be thought to serve as a good background to perturb about.

Authors:
; ;  [1]
  1. School of Physics and Astronomy, University of Nottingham, University Park, Nottingham NG7 2RD (United Kingdom)
Publication Date:
OSTI Identifier:
21413214
Resource Type:
Journal Article
Journal Name:
Physical Review. D, Particles Fields
Additional Journal Information:
Journal Volume: 81; Journal Issue: 12; Other Information: DOI: 10.1103/PhysRevD.81.123501; (c) 2010 The American Physical Society; Journal ID: ISSN 0556-2821
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; ATTRACTORS; BORN-INFELD THEORY; COSMOLOGICAL MODELS; DISTURBANCES; EQUATIONS OF STATE; EVOLUTION; IDEAL FLOW; INFLATIONARY UNIVERSE; MATHEMATICAL SOLUTIONS; PERTURBATION THEORY; PHASE SPACE; SCALING; SOUND WAVES; VELOCITY; EQUATIONS; FLUID FLOW; INCOMPRESSIBLE FLOW; MATHEMATICAL MODELS; MATHEMATICAL SPACE; SPACE; STEADY FLOW

Citation Formats

Copeland, Edmund J, Mizuno, Shuntaro, and Shaeri, Maryam. Cosmological dynamics of a Dirac-Born-Infeld field. United States: N. p., 2010. Web. doi:10.1103/PHYSREVD.81.123501.
Copeland, Edmund J, Mizuno, Shuntaro, & Shaeri, Maryam. Cosmological dynamics of a Dirac-Born-Infeld field. United States. https://doi.org/10.1103/PHYSREVD.81.123501
Copeland, Edmund J, Mizuno, Shuntaro, and Shaeri, Maryam. 2010. "Cosmological dynamics of a Dirac-Born-Infeld field". United States. https://doi.org/10.1103/PHYSREVD.81.123501.
@article{osti_21413214,
title = {Cosmological dynamics of a Dirac-Born-Infeld field},
author = {Copeland, Edmund J and Mizuno, Shuntaro and Shaeri, Maryam},
abstractNote = {We analyze the dynamics of a Dirac-Born-Infeld (DBI) field in a cosmological setup which includes a perfect fluid. Introducing convenient dynamical variables, we show that the evolution equations form an autonomous system when the potential and the brane tension of the DBI field are arbitrary power law or exponential functions of the DBI field. In particular we find scaling solutions can exist when powers of the field in the potential and warp factor satisfy specific relations. A new class of fixed-point solutions are obtained corresponding to points which initially appear singular in the evolution equations, but on closer inspection are actually well defined. In all cases, we perform a phase-space analysis and obtain the late-time attractor structure of the system. Of particular note when considering cosmological perturbations in DBI inflation is a fixed-point solution where the Lorentz factor is a finite large constant and the equation of state parameter of the DBI field is w=-1. Since in this case the speed of sound c{sub s} becomes constant, the solution can be thought to serve as a good background to perturb about.},
doi = {10.1103/PHYSREVD.81.123501},
url = {https://www.osti.gov/biblio/21413214}, journal = {Physical Review. D, Particles Fields},
issn = {0556-2821},
number = 12,
volume = 81,
place = {United States},
year = {Tue Jun 15 00:00:00 EDT 2010},
month = {Tue Jun 15 00:00:00 EDT 2010}
}