Equimultiplicity in Hilbert-Kunz theory
arXiv:1608.07600 · doi:10.1007/s00209-018-2082-5
Abstract
This paper develops a theory of equimultiplicity for Hilbert-Kunz multiplicity and uses it to study the behavior of Hilbert-Kunz multiplicity on the Brenner-Monsky hypersurface. A number of applications follows, in particular we show that Hilbert-Kunz multiplicity attains infinitely many values and that equimultiple strata may not be locally closed.
Update: Added a missing equidimensionality assumption in Proposition 1.22. This does not affect further results since this assumption is present therein