Families of D-minimal models and applications to 3-fold divisorial contractions
arXiv:math/0210048
Abstract
Let X/T be a one parameter family of canonical 3-folds and let D be a Weil divisor on it flat over T. We study the problem of when the D_t-minimal models of X_t form a family and we obtain conditions for this to happen. As an application of this we classify terminal divisorial contractions Y-->X that contract an irreducible divisor E onto a smooth curve C in the case when the general hyperplane section S of X through C is a D5 DuVal singularity.
arXiv commentRevised version. A gap in the proofs of Lemma 2.3 and Theorem 2.4 is corrected. 26 pages