Inhomogeneities in the early universe from the configuration space perspective

We develop a new technique of analyzing the dynamics of cosmological perturbations in the linear regime. The gist of our method, described in Chapters 2 and 3, is to solve the corresponding evolution equations in 1 + 1 space-time dimensions with the initial conditions proportional to a spatial delta function. An arbitrary cosmological perturbation can be described as a superposition of the resulting Green's functions. In Chapter 2 we calculate the Green's functions assuming that prior to recombination photons are tightly coupled to baryons by scattering and neglecting neutrino free-streaming. We find that in the conformal Newtonian gauge a primordial perturbation does not affect the space beyond its acoustic horizon and propagates predominantly as a spherical "shock" that is trailed by a region of finite density and metric perturbation. In Chapter 4 we apply these solutions to analyze the anisotropy of the cosmic microwave background (CMB) radiation. In particular, we observe that wavefront singularities in Green's functions cause temperature anti-correlation for two regions that just established an acoustic contact. The experimental signature of this effect is a distinctive dip in the CMB temperature angular correlation function C([theta]) at [theta][is approzimately equal to] 1.2⁰. Variation of the cosmological parameters [Omega], [Omega]bh2, [Omega]c, n predictably affects the location and the shape of the dip and other C([theta]) characteristics. The acoustic oscillations in CMB angular power spectrum C, appear due to oscillations in the Fourier transform of the Green's functions, having finite spatial extent.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Physics.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2001

Author dc:creator

• Bashinsky, Sergei V. (Sergei Vladimirovich), 1974-

Advisor dc:contributor.advisor

• Edmund Bertschinger.

• Physics.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/8288

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/8288