Structure Formation: Models, Dynamics And Status

Structure Formation: Models, Dynamics and Status

1. Recipe for the Universe All the popular models for structure formation are based on three key ingredients: (a) a model for the background universe (b) some mechanism for generating small perturbations in the early universe and (c) specification of the nature of the dark matter. The background universe is usually taken to be a Friedmann model with an expansion factor a(t). Such a model is com...

Structure formation and generalized second law of thermodynamics in some viable f(R)-gravity models

We investigate the growth of matter density perturbations as well as the generalized second law (GSL) of thermodynamics in the framework of f(R)-gravity. We consider a spatially flat FRW universe filled with the pressureless matter and radiation which is enclosed by the dynamical apparent horizon with the Hawking temperature. For some viable f(R) models containing the Starobinsky, Hu-Sawicki, Exp...

Global Field Dynamics and Cosmological Structure Formation

In this contribution we discuss gravitational effects of global scalar fields and, especially, of global topological defects. We first give an introduction to the dynamics of global fields and the formation of defects. Next we investigate the induced gravitational fields, first in a flat background and then in the expanding universe. In flat space, we explicitly calculate the gravitational fiel...

Non-Equilibrium Dynamics and Structure Formation

Testing Models for Structure Formation

I review a number of tests of theories for structure formation. Large-scale flows and IRAS galaxies indicate a high density parameter Ω ≃ 1, in accord with inflationary predictions, but it is not clear how this meshes with the uniformly low values obtained from virial analysis on scales∼1Mpc. Gravitational distortion of faint galaxies behind clusters allows one to construct maps of the mass sur...