"Linear direct connections "


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In this paper we study the geometry of direct connections in smooth vector

In this paper we study the geometry of direct connections in smooth vector bundles;  we show that the infinitesimal part, Ñt, of a direct connection t is a linear connection. We determine the curvature tensor of the associated linear connection Ñt.

 

As an application of these results, we present a direct proof of N. Teleman's Theorem 6.2. (Direct Connections and Chern Character, Proceedings of the International Conference in Honor of Jean-Paul Brasselet, Luminy, May 2005), which had shown that it was possible to represent the Chern character of smooth vector bundles as the periodic cyclic homology  class of a specific periodic cyclic cycle Ft* , manufactured from a direct connection t, rather than from a smooth linear connection as the Chern - Weil construction does. In addition, we show in this paper that the image of the cyclic cycle Ft*  into the de Rham cohomology (through the A. Connes' isomorphism) coincides with the cycle provided by the Chern - Weil construction applied upon the underlying linear connection Ñt.