English

Integral extensions and the a-invariant

Commutative Algebra 2011-05-31 v1

Abstract

In this note we compare the a-invariant of a homogeneous algebra B to the a-invariant of a subalgebra A. In particular we show that if ABA \subset B is a finite homogeneous inclusion of standard graded domains over an algebraically closed field with A normal and B of minimal multiplicity then A has minimal multiplicity. In some sense these results are algebraic generalizations of Hurwitz type theorems.

Keywords

Cite

@article{arxiv.1105.5722,
  title  = {Integral extensions and the a-invariant},
  author = {Andrew Kustin and Claudia Polini and Bernd Ulrich},
  journal= {arXiv preprint arXiv:1105.5722},
  year   = {2011}
}
R2 v1 2026-06-21T18:14:02.069Z