Hermitian Structures and Compatible Connections on A-bundles

Abstract

A-manifolds and A-bundles are manifolds and vector bundles modelled on a projective finitely generated module over a topological algebra A. In this paper we investigate the conditions under which an A-bundle is provided with an A-valued hermitian structure and a compatible connection, in case A is a commutative complete locally m-convex C*-algebra with unit. In this investigation two obstacles appear: first, A-manifolds do not admit partitions of unity in the classical sence, and, secondly, the existence of a hermitian structure is not equivalent to the reduction of the structural group of the bundle to a certain subgroup. However, we prove that if the bundle has a trivializing covering whose transition functions take values in the group of the "A-hermitian product preserving" automorphisms of the fibre type and the base space admits at least one A-valued partition of unity (subordinate to this covering), then the A-bundle admits an A-hermitian structure and a compatible connection.