Topics in self-interacting random walks

Thumbnail Image
Date
2012-01-01
Authors
Rastegar, Reza
Major Professor
Advisor
Alexander Roiterchtein
Arka Ghosh
Committee Member
Journal Title
Journal ISSN
Volume Title
Publisher
Altmetrics
Authors
Research Projects
Organizational Units
Organizational Unit
Mathematics
Welcome to the exciting world of mathematics at Iowa State University. From cracking codes to modeling the spread of diseases, our program offers something for everyone. With a wide range of courses and research opportunities, you will have the chance to delve deep into the world of mathematics and discover your own unique talents and interests. Whether you dream of working for a top tech company, teaching at a prestigious university, or pursuing cutting-edge research, join us and discover the limitless potential of mathematics at Iowa State University!
Journal Issue
Is Version Of
Versions
Series
Department
Mathematics
Abstract

The principle focus of this thesis is self-interacting random walks. A self-interacting random walk is a walk on a graph with its past influencing its future. In contrast to the regular random walks, self-interacting random walks are genuinely non-Markovian. Correspondingly, most of the standard tools of the theory of random walks are not directly available for the analysis of these models. Typically, this requires a significant adjustment and novel ad-hoc approaches in order to be applied. In this thesis we study two such processes, namely, excited random walks (ERWs) and directionally reinforced random walks (DRRWs).

ERWs have actively attracted many mathematicians in recent years, and several basic questions regarding these random walks on Z^d and trees have been answered. Nonetheless, despite all the effort done of late, there are still fundamental questions about ERWs to be answered. Here, we consider a transient ERW on Z and study the asymptotic behavior of the occupation time of a currently most visited site. In particular, our results imply that, in contrast to the random walks in random environment, a transient excited random walk does not spend an asymptotically positive fraction of time at its favorite (most visited up to a date) sites.

DRRWs were originally introduced by Mauldin, Monticino, and von Weizs"{a}cker. In this thesis, we consider a generalized version of these processes and obtain a stable limit theorem for the position of the random walk in higher dimensions. This extends a result of Horv'{a}th and Shao that was previously obtained in dimension one only.

Comments
Description
Keywords
Citation
Source
Subject Categories
Copyright
Sun Jan 01 00:00:00 UTC 2012