Dissertations, Theses, and Capstone Projects
Date of Degree
9-2026
Document Type
Doctoral Dissertation
Degree Name
Doctor of Philosophy
Program
Mathematics
Advisor
Enrique Pujals
Committee Members
Michael Shub
Ara Basmajian
Subject Categories
Dynamical Systems | Geometry and Topology
Keywords
Topological entropy, homology, intersections
Abstract
A central line of research in dynamical systems concerns the identification of geometric mechanisms necessary and/or sufficient for the production of entropy. In this thesis we prove several technical results directed (in some cases rather obliquely) towards this general project, motivated in particular by problems arising in attempts to prove Shub's entropy conjecture in finite regularity. We first prove a generalization of Poincaré's formula in integral geometry to arbitrary closed manifolds, where the transformation group is replaced by a compact family of C^1 diffeomorphisms satisfying two (essentially optimal) transversality conditions. We give two dynamical applications of this result, first a stochastic Artin-Mazur bound for arbitrary C^1 diffeomorphisms in the presence of sufficiently rich random noise, and second to the construction of uniformly expanding measures on Diff(M). Moving to the C^2 setting, we investigate domination assumptions necessary to guarantee the flatness of Bowen disks on subexponentially shrinking scales. Finally, we answer a question of Correa \& Pujals by constructing a family of subshifts (and smooth realizations) with superpolynomial and subexponential generalized entropy. Returning to the entropy conjecture, we conclude by sketching some directions for future work.
Recommended Citation
Kodat, Axel, "Some Results on Intersections and Entropy" (2026). CUNY Academic Works.
https://academicworks.cuny.edu/gc_etds/6888
