Explicit String bundles

Abstract: While higher bundles are of clear relevance to higher gauge theory, examples other than abelian bundle gerbes are hard to come across. One would in particular like to see 2-bundles where the structure 2-group is the String 2-group associated to a compact simple simply-connected Lie group. This talk will outline a method to construct many examples over homogeneous spaces. We shall also consider one example in detail, giving explicit formulas for the crossed-module-valued Cech cocycle arising from a local trivialisation.