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UBC Theses and Dissertations
Long wavelength cosmological perturbations and preheating Zibin, James Peter
Abstract
This thesis is concerned with the evolution of long wavelength cosmological perturbations in the very early inflationary and post-inflationary stages of the universe. I first provide a thorough review of the relevent theoretical background. This material is presented in a completely original manner, with essentially all of the required results exposed together. Emphasis is made throughout on elucidating the physical meaning of the results. I next perform a study of a particular inflationary model for which there can be explosive growth of long wavelength perturbations due to the process of parametric resonance, and I try to determine whether the backreaction of small scale perturbations is sufficient to save the standard inflationary predictions. I conclude that, for certain parameter values, it is not. Then I describe in considerable detail general aspects of the evolution of long wavelenth modes. I provide a careful link between the evolution of a set of homogeneous background scalar fields, treated as a dynamical system, and the evolution of physical, long wavelength modes. I show that in general we expect several physical modes which cannot be gauged away, and whose evolution depends on the behaviour of the background system. In parametric resonance the resonance can be seen as the instability of a periodic orbit in the background phase space. Finally I demonstrate that another type of background instability, dynamical chaos, can similarly lead to the rapid growth of long wavelength modes.
Item Metadata
Title |
Long wavelength cosmological perturbations and preheating
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Creator | |
Publisher |
University of British Columbia
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Date Issued |
2004
|
Description |
This thesis is concerned with the evolution of long wavelength cosmological perturbations
in the very early inflationary and post-inflationary stages of the universe.
I first provide a thorough review of the relevent theoretical background.
This material is presented in a completely original manner, with essentially
all of the required results exposed together. Emphasis is made throughout on
elucidating the physical meaning of the results. I next perform a study of a
particular inflationary model for which there can be explosive growth of long
wavelength perturbations due to the process of parametric resonance, and I try
to determine whether the backreaction of small scale perturbations is sufficient
to save the standard inflationary predictions. I conclude that, for certain parameter
values, it is not. Then I describe in considerable detail general aspects
of the evolution of long wavelenth modes. I provide a careful link between the
evolution of a set of homogeneous background scalar fields, treated as a dynamical
system, and the evolution of physical, long wavelength modes. I show
that in general we expect several physical modes which cannot be gauged away,
and whose evolution depends on the behaviour of the background system. In
parametric resonance the resonance can be seen as the instability of a periodic
orbit in the background phase space. Finally I demonstrate that another type
of background instability, dynamical chaos, can similarly lead to the rapid
growth of long wavelength modes.
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Extent |
10751710 bytes
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Genre | |
Type | |
File Format |
application/pdf
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Language |
eng
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Date Available |
2009-12-01
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Provider |
Vancouver : University of British Columbia Library
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Rights |
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.
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DOI |
10.14288/1.0085730
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URI | |
Degree | |
Program | |
Affiliation | |
Degree Grantor |
University of British Columbia
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Graduation Date |
2004-05
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Campus | |
Scholarly Level |
Graduate
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Aggregated Source Repository |
DSpace
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Item Media
Item Citations and Data
Rights
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.