Homotopy classes of gauge fields and the lattice
arXiv:1701.00775 · doi:10.4310/ATMP.2019.v23.n8.a7
Abstract
For a smooth manifold , possibly with boundary and corners, and a Lie group , we consider a suitable description of gauge fields in terms of parallel transport, as groupoid homomorphisms from a certain path groupoid in to . Using a cotriangulation of , and collections of finite-dimensional families of paths relative to , we define a homotopical equivalence relation of parallel transport maps, leading to the concept of an extended lattice gauge (ELG) field. A lattice gauge field, as used in Lattice Gauge Theory, is part of the data contained in an ELG field, but the latter contains further local topological information sufficient to reconstruct a principal -bundle on up to equivalence. The space of ELG fields of a given pair is a covering for the space of fields in Lattice Gauge Theory, whose connected components parametrize equivalence classes of principal -bundles on . We give a criterion to determine when ELG fields over different cotriangulations define equivalent bundles.
40 pages, 6 figures. Final version