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Title:Dynamics in neutron stars and the early universe
Author(s):Link, Bennett Karl
Doctoral Committee Chair(s):Baym, Gordon A.
Department / Program:Astronomy
Degree Granting Institution:University of Illinois at Urbana-Champaign
Subject(s):Physics, Astronomy and Astrophysics
Physics, Condensed Matter
Physics, Elementary Particles and High Energy
Abstract:Observations of pulsar timing suggest that glitches and post-glitch behavior are due to variable coupling between the superfluid and normal components in neutron stars. A rotating superfluid is threaded by quantized vortex lines which, in the inner crust of a neutron star, can pin to the nuclear lattice that coexists with the superfluid. The dynamics of the superfluid is described by the motion of these lines. Vortices overcome their pinning barriers through thermal activation or quantum tunneling, and "creep" slowly outward under forces created by the superfluid flow. To the extent that vortices remain pinned, the superfluid retains its angular momentum as the crust slows through interactions with its environment. Catastrophic unpinning of vortices could lead to sudden dissipative coupling between the superfluid and the crust thus creating glitches, while post-glitch relaxation is likely due to the recovery of the vortex creep rate to the steady state.
To explore this model, we develop a microscopic quantum theory for vortex unpinning and creep based on first principles. In considering a range of vortex pinning parameters obtained theoretically, we estimate the vortex creep rate throughout the inner crust. We make predictions for the form and time scales of post-glitch response, and compare with timing data from the Vela and Crab pulsars.
In the second part of the thesis, we study the quark-hadron phase transition in the early universe assuming the transition is first order. First order phase transitions occur dynamically; a bubble of the new phase is nucleated which expands at the expense of the old phase. Using relativistic hydrodynamics, we study the propagation of hadron bubbles with surface tension. We demonstrate the hydrodynamic instability of deflagration processes, and discuss possible consequences for baryon concentration effects relevant in later nucleosynthesis.
Issue Date:1991
Rights Information:Copyright 1991 Link, Bennett Karl
Date Available in IDEALS:2011-05-07
Identifier in Online Catalog:AAI9210897
OCLC Identifier:(UMI)AAI9210897

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