Unified Dark Matter in Scalar Field Cosmologies

Simple item page
dc.creatorBertacca, Daniele
dc.creatorMatarrese, Sabino
dc.creatorPietroni, Massimo
dc.date2007-03-12
dc.date2007-10-29
dc.date.accessioned2026-07-07T11:21:18Z
dc.date.available2026-07-07T11:21:18Z
dc.descriptionConsidering the general Lagrangian of k-essence models, we study and classify them through variables connected to the fluid equation of state parameter w_κ. This allows to find solutions around which the scalar field describes a mixture of dark matter and cosmological constant-like dark energy, an example being the purely kinetic model proposed by Scherrer. Making the stronger assumption that the scalar field Lagrangian is exactly constant along solutions of the equation of motion, we find a general class of k-essence models whose classical trajectories directly describe a unified dark matter/dark energy (cosmological constant) fluid. While the simplest case of a scalar field with canonical kinetic term unavoidably leads to an effective sound speed c_s=1, thereby inhibiting the growth of matter inhomogeneities, more general non-canonical k-essence models allow for the possibility that c_s << 1 whenever matter dominates.
dc.description11 pages LaTeX file, 3 figures. Modified to match the accepted version in Mod. Phys. Lett. A
dc.identifierhttps://arxiv.org/abs/astro-ph/0703259
dc.identifierhttp://arxiv.org/abs/astro-ph/0703259
dc.identifierMod.Phys.Lett.A22:2893-2907,2007
dc.identifierdoi:10.1142/S0217732307025893
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/194226
dc.subjectAstrophysics
dc.subjectGeneral Relativity and Quantum Cosmology
dc.subjectHigh Energy Physics - Phenomenology
dc.titleUnified Dark Matter in Scalar Field Cosmologies
dc.typetext

Files

Collections

arXiv