

Last Thesis

Fundamental Aspects of the Expansion of the Universe and Cosmic
Author:
Tamara M. Davis
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In the context of the new standard LambdaCDM cosmology we resolve conflicts in the literature regarding fundamental aspects of the expansion of the universe and cosmic horizons and we link these concepts to observational tests. We derive the dynamics of a noncomoving galaxy and use this to demonstrate the counterintuitive result that objects at constant proper distance can have a nonzero redshift. Receding galaxies can be blueshifted and approaching galaxies can be redshifted, even in an empty universe for which one might expect special relativity to apply.
We then test the generalized second law of thermodynamics (GSL) and its extension to incorporate cosmological event horizons. In spite of the fact that cosmological horizons do not generally have welldefined thermal properties, we find that the GSL is satisfied for a wide range of models. We explore in particular the relative entropic 'worth' of black hole versus cosmological horizon area. An intriguing set of models show an apparent entropy decrease but we anticipate this apparent violation of the GSL will disappear when solutions are available for black holes embedded in arbitrary backgrounds.
Recent evidence suggests a small increase in the fine structure constant (alpha =e^2/hbar c) over cosmological time scales. This raises the question of which fundamental quantities are truly constant and which might vary. We show that black hole thermodynamics may provide a means to discriminate between alternative theories invoking varying constants, because some variations in the fundamental 'constants' could lead to a violation of the generalized second law of thermodynamics.

Branching Fraction Measurements and SU(3) Diagrammatic Analysis
Author:
Shabana Nisar
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Using 281 inverse pb of data collected using the CLEOc detector, we
present new measurements of Cabibbosuppressed decays of Dmesons. We have
also performed an SU(3) topological analysis and find reasonable agreement
in the Colorsuppressed and Exchange diagram amplitudes between
Cabibbofavored and Cabibbosuppressed decays.

Mixed quantumclassical dynamics: A unified approach to mathemat
Author:
Peter Nettesheim
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The present thesis is devoted to a mathematical analysis of mixed quantumclassical simulations. Since a fully quantum dynamical description of realistic biomolecular systems is by far beyond the scope of simulations, quantum classicl models have attracted considerable attention. They describe most atoms by the means of classical mechanics but an important, small portion of the underlying system by quantum mechanics. Thus, two mathematical topics arise: 1. the analysis of the approximation properties of the models, 2. the development of efficient numerical algorithms for the multiple scales in time and space.
One of the most popular quantumclassical models, the socalled QCMD model, consists of a singularly perturbed Schrödinger equation nonlinearly coupled to classical Newtonian equations. The author discusses a mathematical justification of the QCMD model and the limit dynamics. The homogenization techniques in time used in the latter are compared in application with the method of averaging transformations. Furthermore, novel approaches to the justification of QCMD trajectory bundles are discussed.

ASCA Phd Thesis
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Il link a tesi che utilizzano i dati forniti dal satellite giapponese per l'astronomia X Asca. Tra le tesi che è possibile scaricare si segnalano
3. Xray Measurements of the Mass Distribution in Clusters of Galaxies;
46.XRay Study of Metal Enrichment Processes of Hot Gas in Clusters of Galaxies,
80. Xray Study of Dynamical Evolution in Clusters of Galaxies
87. Xray Study of Distant Clusters of Galaxies: Structure and Evolution.

Excursions in Statistical Dynamics
Author:
Gavin E. Crooks
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There are only a very few known relations in statistical dynamics that are valid for systems driven arbitrarily far away from equilibrium by an external perturbation. One of these is the fluctuation theorem, which places conditions on the entropy production probability distribution of nonequilibrium systems. Another recently discovered farfromequilibrium expression relates nonequilibrium measurements of the work done on a system to equilibrium free energy differences. In contrast to linear response theory, these expressions are exact no matter the strength of the perturbation, or how far the system has been driven from equilibrium. In this work I show that these relations (and several other closely related results) can all be considered special cases of a single theorem. This expression is explicitly derived for discrete time and space Markovian dynamics, with the additional assumptions that the unperturbed dynamics preserve the appropriate equilibrium ensemble, and that the energy of the system remains finite.



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