Almost Commuting Elements in Compact Lie Groups

Download or read book Almost Commuting Elements in Compact Lie Groups written by Armand Borel and published by American Mathematical Soc.. This book was released on 2002 with total page 153 pages. Available in PDF, EPUB and Kindle. Book excerpt: This text describes the components of the moduli space of conjugacy classes of commuting pairs and triples of elements in a compact Lie group. This description is in the extended Dynkin diagram of the simply connected cover, together with the co-root integers and the action of the fundamental group. In the case of three commuting elements, we compute Chern-Simons invariants associated to the corresponding flat bundles over the three-torus, and verify a conjecture of Witten which reveals a surprising symmetry involving the Chern-Simons invariants and the dimensions of the components of the moduli space.