| Abstract: |
The concentration of measure phenomenon was first discovered in the 1930's
by Paul Levy and has been investigated since then, with increasing
intensity in recent decades. The probability-theoretic results have
been gradually percolating throughout the mathematical community,
finding applications in Banach space geometry, analysis of algorithms,
statistics and machine learning.
There are several approaches to proving concentration of measure
results; we shall offer a brief survey of these. The principal
contribution of this thesis is a new concentration inequality for
nonproduct measures. The inequality is proved by elementary means,
yet enables one, with minimal effort, to recover and generalize the
best current results for Markov chains, as well as to obtain new results
for hidden Markov chains and Markov trees.
As an application of our inequalities, we give a strong law of large
numbers for a broad class of non-independent processes. In particular,
this allows one to analyze the convergence of inhomogeneous Markov
Chain Monte Carlo algorithms. We also give some partial results on
extending the Rademacher-type generalization bounds to processes with
arbitrary dependence.
Committee:
John Lafferty, CMU (Chair)
Kavita Ramanan, CMU
Larry Wasserman, CMU
Gideon Schechtman, Weizmann Institute of Science |