Fermionic topological charge of families of lattice gauge fields

Abstract

Topological charge of families of lattice gauge fields is defined fermionically via families index theory for the overlap Dirac operator. Certain obstructions to gauge invariance of the overlap chiral fermion determinant, as well as the lattice analogues of certain obstructions to gauge fixings without the Gribov problem, have natural descriptions in this context.

Comments: 4p., Lattice2002(chiral) (+ one paragraph not included in the proceedings version for length reasons)