Birational stability of the orbifold cotangent bundle
De Frédéric Campana
Apparaît dans la collection : Complex Analytic and Differential Geometry
We investigate the holonomy group of singular Kähler-Einstein metrics on klt varieties with numerically trivial canonical divisor. Finiteness of the number of connected components, a Bochner principle for holomorphic tensors, and a connection between irreductibility of holonomy representations and stability of the tangent sheaf are established. As a consequence, we show that up to finite quasi-étale covers, varieties with strongly stable tangent sheaf are either Calabi-Yau (CY) or irreducible holomorphic symplectic (IHS). Finally, finiteness properties of fundamental groups of CY and IHS varieties are established.