<?xml version="1.0" encoding="UTF-8"?>
<rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom"><channel>
<title>Hollis Williams — Neckpinch</title><link>https://neckpinch.com/authors/hollis-williams/</link><description>New arXiv papers by Hollis Williams, from Neckpinch</description>
<atom:link href="https://neckpinch.com/authors/hollis-williams/rss.xml" rel="self" type="application/rss+xml"/><lastBuildDate>Tue, 03 Nov 2026 08:41:12 GMT</lastBuildDate>
<item><title>Monotonicity of the Cheeger constant under Ricci flow on spheres</title><link>https://neckpinch.com/papers/2404.13063/</link><guid isPermaLink="false">arxiv:2404.13063</guid><pubDate>Fri, 12 Apr 2024 00:00:00 GMT</pubDate><description>Hollis Williams — We study the behavior of the Cheeger isoperimetric constant under the Ricci flow on compact surfaces. For metrics on a surface diffeomorphic to S², we show that the Cheeger constant is non-decreasing along the flow. The proof uses evolution identities for parallel curves together with a viscosity formulation of the evolution of log h which accommodates for the possible switching of minimizing regions. We also give examples of nontrivial Ricci flows on topological 2-spheres for which the Cheeger constant remains constant, demonstrating that strict monotonicity is not expected.</description><category>Ricci flow</category><category>Surfaces</category><category>Geometric inequalities</category></item>
</channel></rss>