On Localization of Tight Closure in Line- Quartics
arXiv:2211.03220
Abstract
Building on work of Brenner and Monsky from 2010 and on a Hilbert-Kunz calculation of Monsky from 1998, we exhibit a novel example of a hypersurface over in which tight closure does not commute with localization. Our methods involve a surprising tiling argument using Sierpiński triangles, as well as an inspection of a certain dynamical system in characteristic two.
Written during the 2022 SMALL REU at Williams College. Comments welcome