Dissertations, Theses, and Capstone Projects

Date of Degree

9-2026

Document Type

Doctoral Dissertation

Degree Name

Doctor of Philosophy

Program

Mathematics

Advisor

Matthew Junge

Advisor

Tobias Johnson

Committee Members

Elena Kosygina

Subject Categories

Discrete Mathematics and Combinatorics | Other Mathematics

Abstract

We demonstrate many of the conjectured universality and self-organized criticality (SOC) properties of the interacting particle system Activated Random Walk (ARW) in the setting of one-dimensional biased walks, as formulated for instance in Levine and Silvestri’s 2024 survey. Namely, there exists the same limiting critical state for two finite ARW models, as well as for the infinite model as the density approaches its critical value from below. Many of the desired properties hold, including heavy-tailed avalanches, but spatial correlations decay exponentially fast, a deviation from the SOC paradigm. Nonetheless, the obtained decay rate vanishes with the bias. Since the critical state varies continuously with the bias and has monotonic density, it feasibly converges to the critical state for symmetric ARW. Finally, we prove the conjectured non-fixation behavior at criticality.

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