INTERACTING COSMIC FLUIDS IN BRANS–DICKE COSMOLOGY

Cosmic Walls and Filaments Formation in Modied Chaplygin Gas Cosmology

We want to study the perturbation growth of an initial seed of an ellipsoidal shape in Top-Hat collapse model of the structure formation in the Modied Chaplygin gas cosmology. Considering reasonable values of the constants and the parameters of the model under study, we can show that a very small deviation from spherical symmetry (ellipsoidal geometry) in the initial seed leads to a nal highly ...

Interacting Constituents in Cosmology

Universe evolution, as described by Friedmann’s equations, is determined by source terms fixed by the choice of pressure × energy-density equations of state p (ρ). The usual approach in Cosmology considers equations of state accounting only for kinematic terms, ignoring the contribution from the interactions between the particles constituting the source fluid. In this work the importance of the...

Cosmic Defects and Cosmology

We provide a pedagogical overview of defect models of structure formation. We first introduce the concept of topological defect, and describe how to classify them. We then show how defects might be produced in phase transitions in the Early Universe and approach non-pathological scaling solutions. A very heuristic account of structure formation with defects is then provided, following which we ...

Cosmology and the Cosmic Microwave

Cosmic Gravitational Wave Background in String Cosmology

String cosmology models predict a stochastic cosmic background of gravitational waves with a characteristic spectrum. I describe the background, present astrophysical and cosmological bounds on it, and outline how it may be possible to detect it with gravitational wave detectors.