Dynamics of primordial phase transitions, primordial magnetic fields, and Big Bang nucleosynthesis

In this thesis, I have studied the dynamics of the inflationary universe and the possible cosmological consequences of a series of phase transitions which the universe may have undergone. Specially, I have studied the dynamics of primordial phase transitions, primordial magnetic fields, and Big Bang Nucleosynthesis. In particular, (1) I have derived the effects of magnetic fields on nucleon and particle reaction rates of astrophysical significance. The sensitivity to the presence of arbitrary degeneracy and polarization has also been examined. (2) I have calculated the effects of magnetic fields on Big Bang Nucleosynthesis and explored the impacts on the abundances of the light elements numerically. An upper limit on the strength and coherence scale of primordial magnetic fields compatible with observations of light element abundances has been placed. (3) I have proposed a new mechanism by which a magnetic field of magnitude $10\sp6$ gauss is generated on scales of 44m at the quark-hadron phase transition. The possibility of further enhancements due to dynamo action and of the astrophysical applications are discussed. (4) I have explored the dynamics of a general first order phase transition. A covariant jump condition across a bubble wall, including surface tension and dissipation, for a nongravitational moving surface, has been derived. Specially, the cosmological quark-hadron phase transition has been examined as a specific application of the general formalism, and the possible mechanism of energy transport during the phase transition is studied. (5) I have examined the role of bulk viscosity in the inflationary universe during the GUT phase transition and its effects on cosmological inflation, density fluctuations, and entropy production. Finally, I have investigated the role of gravitation in an inflationary universe and the possible relationship between gravity and inflation. The initial condition and the identification of inflation problems are probed in the framework of scalar-tensor theories of gravity. An extended inflationary cosmological model has been proposed.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Astronomy

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2011

Author dc:creator

• Cheng, Baolian

Contributors dc:contributor

• Truran, James W.
• Schramm, David N.

• Physics, Astronomy and Astrophysics

Statement dc:rights

• Copyright 1993 Cheng, Baolian

Language dc:language

eng

Identifier

AAI9411587
(UMI)AAI9411587

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/22315