Linear Growth of Matter Density Perturbations in Theories

Cosmic Strings, Loops, and Linear Growth of Matter Perturbations

We describe a detailed study of string-seeded structure formation using high resolution numerical simulations in open universes and those with a non-zero cosmological constant. We provide a semi-analytical model which can reproduce these simulation results including the effect from small loops chopped of by the string network. A detailed study of cosmic string network properties regarding struc...

Dark Matter, Density Perturbations and Structure Formation

his paper provides a review of the variants of dark matter (CDM, HDM) which are thought to be fundamental components of the universe and their role in origin and evolution of structures. Introduction The origin and evolution of large scale structure is today the outstanding problem in cosmology. This is the most fundamental question we can ask about the universe whose solution should help us to...

Week 4: The growth of density perturbations

Over the past few decades, a number of surveys (most recently the Sloan Digital Sky Survey and the Two-Degree Field) have measured the redshifts of thousands, and now even millions, of galaxies and used them to plot the three-dimensional distribution of galaxies in the Universe. The conclusion is that if we smooth the distribution on the largest scales (larger than several hundred Mpc scales), ...

Are any growth theories linear?∗

Growth of perturbations in dark matter coupled with quintessence

We consider the evolution of linear perturbations in models with a nonminimal coupling between dark matter and scalar field dark energy. Growth of matter inhomogeneities in two examples of such models proposed in the literature are investigated in detail. Both of these models are based on a low-energy limit of effective string theory action, and have been previously shown to naturally lead to l...