Algebraic Geometry Seminar
John Lesieutre
MIT
Counterexamples to some positivity questions
Abstract: I will explain the failure of several "positivity"
properties of divisors: nefness is not an open condition in families;
the diminished base locus of a divisor is not always a closed set;
Zariski decompositions do not necessarily exist in dimension three;
and asymptotic multiplicity invariants are not always finite in the
relative setting.
Wednesday November 13, 2013 at 4:00 PM in SEO 427