Physical Sciences and Mathematics Commons^™

Quantitative K-Theory And Spin Chern Numbers [Dataset], Terry A. Loring

Math and Statistics Datasets

We examine the various indices defined on pairs of almost commuting unitary matrices that can detect pairs that are far from commuting pairs. We do this is two symmetry classes, that of general unitary matrices and that of self-dual matrices, with an emphasis on quantitative results. We determine what values of the norm of the commutator guarantee that the indices are defined, where they are equal, and what quantitative results on the distance to a pair with a different index are possible. We validate a method of computing spin Chern numbers that was developed with Hastings and only conjectured to …