English

On Strongly $F$-Regular Inversion of Adjunction

Algebraic Geometry 2015-04-17 v4 Commutative Algebra

Abstract

In this article we give two independent proofs of the positive characteristic analog of the log terminal inversion of adjunction. We show that for a pair (X,S+B)(X, S+B) in characteristic p>0p>0, if (Sn,BSn)(S^n, B_{S^n}) is strongly FF-regular, then SS is normal and (X,S+B)(X, S+B) is purely FF-regular near SS. We also answer affirmatively an open question about the equality of FF-Different and Different.

Cite

@article{arxiv.1310.8252,
  title  = {On Strongly $F$-Regular Inversion of Adjunction},
  author = {Omprokash Das},
  journal= {arXiv preprint arXiv:1310.8252},
  year   = {2015}
}

Comments

A new proof of the Proposition 3.4 is given as per referee's suggestion and some other minor changes in some lemmas. Comments are welcome

R2 v1 2026-06-22T01:57:41.757Z