Seshadri constants for curve classes

Abstract

We develop a local positivity theory for movable curves on projective varieties similar to the classical Seshadri constants of nef divisors. We give analogues of the Seshadri ampleness criterion, of a characterization of the augmented base locus of a big and nef divisor, and of the interpretation of Seshadri constants as an asymptotic measure of jet separation. We also study the case of arbitrary codimension.

arXiv commentLemma 4.4 and Examples 4.5 and 5.3 are new. Some typos fixed. Comments welcome