The October 27, 2014 O.M.N.I. Talk: Ashley Wheeler presents

Divisors

Abstract: Stated informally, a (Weil) divisor on a variety X is a formal sum of codimension 1 subvarieties. We define this notion more precisely for irreducible varieties and define the divisor class group, an important invariant of an algebraic variety. In general, the divisor class group is HARD to compute. In this talk we give a handful of examples where it is possible.