Dissertation > Excellent graduate degree dissertation topics show
Effects of Modified Chaplygin Gas as Dark Energy on Structure Formation in Universe by Using Spherical Collapse Theory
Author: SuYangYang
Tutor: WuYaBo
School: Liaoning Normal University
Course: Theoretical Physics
Keywords: dark energy modified Chaplygin gas nonlinear perturbation spherical collapsemodel cluster abundance
CLC: P159
Type: Master's thesis
Year: 2012
Downloads: 2
Quote: 0
Read: Download Dissertation
Abstract
In recent years, the accurate observation data from SNe la, WMAP and SDSS indicate that the expansion of the universe is accelerating, which becomes one of the popular questions of the physics. But this result seem to conflict with the standard big bang cosmological model which is familar to us. In order to alleviate the contradiction, many theories have been proposed. There are two major kinds of mainline correction method:one is introducing new component of cosmic which is called dark energy with negative pressure, which is a homogeneous distribution in the big scale structure. The introduction of dark energy is actually a correction of the right of Einstein gravitational field equation. Alternative to it, we can consider modifying the part of geometry in the left of the Einsteinâ€™s equation.In this text,we will further investigate the effects of modified Chaplygin gas on the structure formation of universe in a flat universe. The background knowledge of modern cosmology is fist introduced, and we review the standard cosmology model then briefly give the summaries of the current established various dark energy model. Next we introduce the spherical collapse model and cluster cluster number counts in structure formation, which could combine the parameters of model with observation data, consequently distinguishing and estimating various dark energy models. So in the third part we specifically introduce the related research theory and method. In the following section, we select modified Chaplygin gas (MCG) model to specific application of the theory. After reviewing the relevant dynamic evolution of MCG, we discuss the influence of MCG as dark energy to structure formation with the spherical collapse model in nonlinear regime, and divide the nonlinear process into two phases, the first process is from forming small density contrast to expanding until turnaround state. The second process is from turnaround state to virialation. We respectively discuss the density contrast of turnaround and virialation, and compare the results with GCG, LCDM, Einsteinde sitter. For the linear regime, we just choose some cosmology parameters to research, and make the contrast with the observation, the result consists well with observation. Therefor the model of modified Chaplygin gas as dark energy could explain the accelerating universe well in linear and nonlinear perturbations. Finally we use Pressshceter mass function to calculate the evolution of the cluster abundance in different ranges of mass, and contrast the result with the standard LCDM model, GCG model and parameterized dark energy model.

Related Dissertations
 Localization of WMAP NonGaussian Regions and Correlations with Foreground Galaxies,P159
 The Application of General Relativity: Hawking Radiation of the Black Hole and GPS Navigation,P228.4
 A Study of the Influence of Viscosity for the Evolution of the Universe,P159
 Modified Chaplygin gas (MCG) structure formed,P159
 The Research on New Generalized Chaplygin Gas Model and Its Relative Problems,P159
 Theoretical research on holographic dark energy in the BransDicke universe,P145.9
 Dark energy model and its analysis and comparison,P145.9
 MOND with some theoretical studies gravitational entropy,P145.9
 Robust Stability of network control system,TP273
 The Evolution of the Variable Generalized Chaplygin Gas and Its Effect on the Structure Formation of the Universe,P159
 Statefinder Diagnostic for Two Cosmological Models,P159.3
 Evolution of Dark Energy and Statefinder Diagnosis in the Modified Chaplygin Gas Model with Varying Coupling,O314
 A Study on the Dynamic Stability and the Property of Interaction of Generalized Chaplygin Gas,P145.9
 A Study of Holographic Dark Energy in Interacting Modified Chaplygin Gas Model,P159
 ModelBased Control of Singularly Perturbed Networked Systems with Uncertain Nonlinear Disturbance,O231
 Research on LTB Universe and Its Related Issues,P159
 On Two iHolgraphic Dark Energy Models,P145.9
 Geometrical Diagnostic and Phasespace Analysis of Dark Energy Models,P145.9
 Stability Analysis and Robust Control of Nonlinear Systems with Time Delay,TP13
 Study of Quintom Dark Energy Model in Spinor Field,P159
 Analysis and Design of Robust Performance for Uncertain Timedelay Systems,TP13
CLC: > Astronomy,Earth Sciences > Astronomy > Stellar astronomy,galactic astronomy,cosmology > Cosmology
© 2012 www.DissertationTopic.Net Mobile
