Évènements

Hodge-Riemann relations and Schur classes

Catégorie d'évènement : Séminaire de géométrie complexe Date/heure : 16 septembre 2019 14:00-15:00 Lieu : Oratrice ou orateur : Julius Ross Résumé :

As is well known, Hodge Theory for projective manifolds has a number of topological consequences, particularly through the Hard-Lefschetz Theorem and the Hodge-Riemann bilinear relations. Classically this theory involves a positive cohomology class, for instance the first Chern class of an ample line bundle. In this talk I will discuss an extension of this package of ideas to Schur classes of ample vector bundles. I will also discuss various consequences, including a higher-rank version of the famous Khovanskii-Teissier inequalities and some applications to algebraic combinatorics. This work is joint with Matei Toma.


Effective global generation on manifolds with numerically trivial canonical bundle

Catégorie d'évènement : Séminaire de géométrie complexe Date/heure : 16 septembre 2019 15:30-16:30 Lieu : Oratrice ou orateur : Alex Kà¼ronya Résumé :

If L is a line bundle on a projective manifold, then the existence of effective bounds for its tensor powers to have global sections or become globally generated have been a central problem in algebaic geometry for the last 150 years. While the case of curves follows from Riemann-Roch, satsifactory answers for surfaces only arrived about thirty years ago. Research in the area has been mostly motivated by Fujita’s conjectures predicting the global generation and very ampleness of certain adjoint line bundles. In this talk we will consider the case of effective global generation for projective manifolds with numerically trivial canonical bundle. This is an account of joint work with Yusuf Mustopa.