Braided Hopf algebras and gauge transformations

We study infinitesimal gauge transformations of K-equivariant noncommutative principal bundles, for K a triangular Hopf algebra. They form a Lie algebra of derivations in the category of K-modules. We study Drinfeld twist deformations of these infinitesimal gauge transformations. We give several examples from abelian and Jordanian twist deformations. These include the quantum Lie algebra of gauge transformations of the instanton bundle and of the orthogonal bundle on the quantum sphere \(S^4_\theta \) $S_{\theta }^4$ .