Institute for Mathematical Physics Projective Holonomy I: Principles and Properties Projective Holonomy I: Principles and Properties

The aim of this paper and its sequel is to introduce and classify the holonomy algebras of the projective Tractor connection. After a brief historical background, this paper presents and analyses the projective Cartan and Tractor connections, the various structures they can preserve, and their geometric interpretations. Preserved subbundles of the Tractor bundle generate foliations with Ricci-flat leaves. Contactand Einstein-structures arise from other reductions of the Tractor holonomy, as do U(1) and Sp(1,H) bundles over a manifold of smaller dimension.