Cartan geometries and multiplicative forms

Characteristic Forms of Complex Cartan Geometries

We calculate relations on characteristic classes which are obstructions preventing closed Kähler manifolds from carrying holomorphic Cartan geometries. We apply these relations to give global constraints on the phase spaces of complex analytic determined and underdetermined systems of differential equations.

Institute for Mathematical Physics Parabolic Geometries and Canonical Cartan Connections Parabolic Geometries and Canonical Cartan Connections

Let G be a (real or complex) semisimple Lie group, whose Lie algebra g is endowed with a so called jkj{grading, i.e. a grading of the form g = g ?k g k , such that no simple factor of G is of type A 1. Let P be the subgroup corresponding to the subalgebra p = g 0 g k. The aim of this paper is to clarify the geometrical meaning of Cartan connections corresponding to the pair (G; P) and to study ...

Parabolic Geometries and Canonical Cartan Connections

Let G be a (real or complex) semisimple Lie group, whose Lie algebra g is endowed with a so called |k|–grading, i.e. a grading of the form g = g−k ⊕ · · · ⊕ gk, such that no simple factor of G is of type A1. Let P be the subgroup corresponding to the subalgebra p = g0 ⊕ · · · ⊕ gk. The aim of this paper is to clarify the geometrical meaning of Cartan connections corresponding to the pair (G,P )...

Killing Fields of Holomorphic Cartan Geometries

We study local automorphisms of holomorphic Cartan geometries. This leads to classification results for compact complex manifolds admitting holomorphic Cartan geometries. We prove that a compact Kähler Calabi-Yau manifold bearing a holomorphic Cartan geometry of algebraic type admits a finite unramified cover which is a complex

Twistor Spinors and Normal Cartan Connections in Conformal Geometries