Evolution of Perturbations in a Domain Wall Cosmology
نویسنده
چکیده
A fluid of domain walls may have an effective equation of state pw = − 23ρw. This equation of state is qualitatively in agreement with the supernova type Ia observations. We exploit a cosmological model where the matter content is given by a dust fluid and a domain wall fluid. The process of formation of galaxies is essentially preserved. On the other hand, the behaviour of the density contrast in the ordinary fluid is highly altered when domain walls begin to dominate the matter content of the Universe. This domain wall phase occurs at relative recent era, and its possible consequences are discussed, specially concerning the Sachs-Wolfe effect.
منابع مشابه
On the Evolution of Scalar Metric Perturbations in an Innationary Cosmology
We further clarify how scalar metric perturbations are ampliied in an innationary cosmology. We rst construct a simple, analytic model of an in-ationary cosmology in which the expansion scale factor evolves continuously from an innationary era to a radiation-dominated era. From this model, it is clear to see how scalar perturbations are ampliied. Second, we examine the recent claims of Grishchu...
متن کاملEvolution of cosmological perturbations in a brane-universe.
In our present Letter, we analyze the impact of the existence of extra dimensions on cosmology, in particular, on the evolution of cosmological perturbations. For a five-dimensional anti-de Sitter spacetime where ordinary matter is confined to a brane-universe, the equations governing the cosmological perturbations are presented in a form very close to the equations of standard cosmology. Two t...
متن کامل0 Brane New World
We study a Randall-Sundrum cosmological scenario consisting of a domain wall in anti-de Sitter space with a strongly coupled large N conformal field theory living on the wall. The AdS/CFT correspondence allows a fully quantum mechanical treatment of this CFT, in contrast with the usual treatment of matter fields in inflationary cosmology. The conformal anomaly of the CFT provides an effective t...
متن کاملBuoyancy Term Evolution in the Multi Relaxation Time Model of Lattice Boltzmann Method with Variable Thermal Conductivity Using a Modified Set of Boundary Conditions
During the last few years, a number of numerical boundary condition schemes have been used to study various aspects of the no-slip wall condition using the lattice Boltzmann method. In this paper, a modified boundary condition method is employed to simulate the no-slip wall condition in the presence of the body force term near the wall. These conditions are based on the idea of the bounce-back ...
متن کاملThe braneworld stability and large-scale correction in graphene like background
In this work, we consider a graphene-like background in braneworld scenario which is one of the interesting models in cosmology and theoretical physics. Indeed, this paper is an application of holography in condense matter. We use the geometric form of potential which help to obtain field equations and solve it to obtain the energy spectrum. In that case we calculate superpotential and energy d...
متن کامل