Cosmological dynamics of a Dirac-Born-Infeld field

Journal Article · Tue Jun 15 00:00:00 EDT 2010 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.81.123501· OSTI ID:21413214

Copeland, Edmund J; Mizuno, Shuntaro; Shaeri, Maryam ^[1]

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1. School of Physics and Astronomy, University of Nottingham, University Park, Nottingham NG7 2RD (United Kingdom)

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.

• OSTI ID: 21413214
• Journal Information: Physical Review. D, Particles Fields, Vol. 81, Issue 12; Other Information: DOI: 10.1103/PhysRevD.81.123501; (c) 2010 The American Physical Society; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

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