Chiara Pagani
University of Bologna, Bologna, Italy

Hopf-Galois algebra extensions are seen as principal bundles in noncommutative geometry. In this context, it is an open problem the definition of algebraic counterparts of the groups of bundle automorphisms and gauge transformations. I will present recent results on the study of braided Lie and Hopf algebras of infinitesimal gauge transformations for noncommutative $H$-Galois algebra extensions which are equivariant ($H$-$K$ Hopf modules) under a triangular Hopf algebra $K$. Seminar based on joint works with P. Aschieri (Piemonte Orientale) and G. Landi (Trieste).