The jumping coefficients of non-Q-Gorenstein multiplier ideals
Abstract
Let be a coherent ideal sheaf on a normal complex variety , and let be a real number. De Fernex and Hacon associated a multiplier ideal sheaf to the pair which coincides with the usual notion whenever the canonical divisor is -Cartier. We investigate the properties of the jumping numbers associated to these multiplier ideals. We show that the set of jumping numbers of a pair is unbounded, countable and satisfies a certain periodicity property. We then prove that the jumping numbers form a discrete set of real numbers if the locus where fails to be -Cartier is zero-dimensional. It follows that discreteness holds whenever is a threefold with rational singularities. Furthermore, we show that the jumping numbers are rational and discrete if one removes from a closed subset of codimension at least three, which does not depend on . We also obtain that outside of , the multiplier ideal reduces to the test ideal modulo sufficiently large primes .
Keywords
Cite
@article{arxiv.1410.5091,
title = {The jumping coefficients of non-Q-Gorenstein multiplier ideals},
author = {Patrick Graf},
journal= {arXiv preprint arXiv:1410.5091},
year = {2020}
}