Ruan's conjecture and integral structures in quantum cohomology

Abstract

This is an expository article on the recent studies of Ruan's crepant resolution/flop conjecture and its possible relations to the K-theory integral structure in quantum cohomology.

38 pages; Submitted to the proceedings of the conference "New developments in Algebraic Geometry, Integrable Systems and Mirror symmetry" held at RIMS, January, 2008