Cosmology with decaying tachyon matter

Abstract

We investigate the case of a homogeneous tachyon field coupled to gravity in a spatially flat Friedman-Robertson-Walker spacetime. Assuming the field evolution to be exponentially decaying with time we solve the field equations and show that, under certain conditions, the scale factor represents an accelerating universe, following a phase of decelerated expansion. We make use of a model of dark energy (with p=-ρ) and dark matter (p=0) where a single scalar field (tachyon) governs the dynamics of both the dark components. We show that this model fits the current supernova data as well as the canonical \LambdaCDM model. We give the bounds on the parameters allowed by the current data.

14 pages, 6 figures, v2, Discussions and references addeded

References in corpus (8)

• Type Ia Supernova Discoveries at z>1 From the Hubble Space Telescope: Evidence for Past Deceleration and Constraints on Dark Energy Evolution
• WMAP constraints on low redshift evolution of dark energy
• Dark Energy: the Cosmological Challenge of the Millennium
• Slow-roll parameters in braneworld cosmologies
• A Note on Inflation with Tachyon Rolling on the Gauss-Bonnet Brane
• Accelerating Universes and String Theory
• Scalar field potentials for cosmology
• Curvature Coupling and Accelerated Expansion of the Universe

Cited by in corpus (29)

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• Observational constraints on low redshift evolution of dark energy: How consistent are different observations?
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• Dark Energy Model in Anisotropic Bianchi Type-III Space-Time with Variable EoS Parameter
• Inflation and dark energy arising from geometrical tachyons
• Scalar Field Dark Energy Perturbations and their Scale Dependence
• Accelerating dark energy models with anisotropic fluid in Bianchi type-$V{I}_0$ space-time
• Can cosmological observations uniquely determine the nature of dark energy ?
• Constraining non-minimally coupled tachyon fields by Noether symmetry
• Why Does Gravity Ignore the Vacuum Energy?
• Inflation from D3-brane motion in the background of D5-branes
• Cosmology With Non-Minimally Coupled K-Field
• Born-Infeld cosmology with scalar Born-Infeld matter
• Evolution of perturbations in distinct classes of canonical scalar field models of dark energy
• Dark Energy Models With Variable Equation Of State Parameter
• Lorentz covariant statistical mechanics and thermodynamics of the relativistic ideal gas and preferred frame
• Dynamics of generalized tachyon field
• Dark Energy Nature in Logarithmic $f(R,T)$ Cosmology
• Cosmological Scaling Solutions with Tachyon:Modified Gravity Model
• Logamediate Inflation by Tachyon Field
• A Quintessentially Geometric Model
• Dark Sector from Interacting Canonical and Non-Canonical Scalar Fields
• Relativistic ideal Fermi gas at zero temperature and preferred frame
• Field independent cosmic evolution
• Tachyonization of the $\La$CDM cosmological model
• Evolution of Dark Energy Perturbations for Slotheon Field and Power Spectrum
• Role of Tachyonic Field in Accelerating Universe in Presence of Perfect Fluid
• Inflation driven by single geometric tachyon with D-brane orbiting around NS5-branes
• Dynamical System Analysis of Randall-Sundrum Model with Tachyon Field on the Brane