A formula for the *-core of an ideal
arXiv:0910.4597
Abstract
Expanding on the work of Fouli and Vassilev \cite{FV}, we determine a formula for the *- of an ideal in two different settings: (1) in a Cohen--Macaulay local ring of characteristic , perfect residue field and test ideal of depth at least two, where the ideal has a minimal *-reduction that is a parameter ideal and (2) in a normal local domain of characteristic , perfect residue field and $\m$-primary test ideal, where the ideal is a sufficiently high Frobenius power of an ideal. We also exhibit some examples where our formula fails if our hypotheses are not met.
11 pages, submitted for publication