

Ergodic theory of the geodesic flow of hyperbolic surfaces - Lecture 1
By Barbara Schapira


Ergodic theory of the geodesic flow of hyperbolic surfaces - Lecture 2
By Barbara Schapira
Appears in collections : French-German meeting on complex algebraic geometry / Rencontre franco-allemande en géométrie algébrique complexe, Exposés de recherche
Simpson’s classic nonabelian Hodge correspondence establishes an equivalence of categories between local systems on a projective manifold, and certain Higgs sheaves on that manifold. This talk surveys recent generalisations of Simpson’s correspondence to the context of projective varieties with klt singularities. Perhaps somewhat surprisingly, these spaces exhibit two correspondences: one pertaining to local systems on the whole space, and one to local systems on its smooth locus. As one application, we resolve the quasi-étale uniformisation problem for minimal varieties of general type, and to obtain a complete numerical characterisation of singular quotients of the unit ball by discrete, co-compact groups of automorphisms that act freely in codimension one.