The purpose of this paper is to define and study systematically some
asymptotic invariants associated to base loci of line bundles on smooth
projective varieties. We distinguish an open dense subset of the real big cone,
called the stable locus, consisting of the set of classes on which the
asymptotic base locus is locally constant. The asymptotic invariants define
continuous functions on the big cone, whose vanishing characterizes, roughly
speaking, the unstable locus. We show that for toric varieties at least, there
exists a polyhedral decomposition of the big cone on which these functions are
polynomial.Comment: 26 pages, 1 figure; shorter version with more efficient exposition
and more general version of asymptotic invariants; notation changed,
references added, minor mistakes correcte
