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dc.contributor.advisorEdmund Bertschinger.en_US
dc.contributor.authorBashinsky, Sergei V. (Sergei Vladimirovich), 1974-en_US
dc.contributor.otherMassachusetts Institute of Technology. Dept. of Physics.en_US
dc.date.accessioned2005-08-23T18:54:44Z
dc.date.available2005-08-23T18:54:44Z
dc.date.copyright2001en_US
dc.date.issued2001en_US
dc.identifier.urihttp://hdl.handle.net/1721.1/8288
dc.descriptionThesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Physics, 2001.en_US
dc.descriptionIncludes bibliographical references (p. 103-106).en_US
dc.description.abstractWe 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.en_US
dc.description.abstractThe finite extent and monotonicity of Green's functions greatly reduce CPU time required for numerical calculation of perturbation dynamics. The geometrical part of the calculations connecting the early universe inhomogeneities with the CMB anisotropy spectrum C, in momentum space, can also be sped up by averaging the contributions from different momentum modes over rapid oscillations of a geometrical term. In Chapter 5 we describe implementation of these two ideas as a computer program calculating CMB spectrum within the fluid approximation of Chapter 2. In Chapter 3 we extend Green's function techniques to Boltzmann phase space to incorporate diffusion of massless particles. We obtain a solution for adiabatic perturbations in the radiation dominated universe that includes the dynamics of perturbations in the cosmic background of massless neutrinos.en_US
dc.description.statementofresponsibilityby Sergei V. Bashinsky.en_US
dc.format.extent106 p.en_US
dc.format.extent5724166 bytes
dc.format.extent5723928 bytes
dc.format.mimetypeapplication/pdf
dc.format.mimetypeapplication/pdf
dc.language.isoengen_US
dc.publisherMassachusetts Institute of Technologyen_US
dc.rightsM.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.en_US
dc.rights.urihttp://dspace.mit.edu/handle/1721.1/7582
dc.subjectPhysics.en_US
dc.titleInhomogeneities in the early universe from the configuration space perspectiveen_US
dc.typeThesisen_US
dc.description.degreePh.D.en_US
dc.contributor.departmentMassachusetts Institute of Technology. Dept. of Physics.en_US
dc.identifier.oclc50420420en_US


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