Sesión Geometría Algebraica y Teoría de Números

Diciembre 12, 15:30 ~ 16:10

Orbital degeneracy loci

Laurent, Manivel

Degeneracy loci of morphisms between vector bundles have been used in a wide variety of situations. This notion can be vastly generalized, starting from orbit closures of algebraic groups in their linear representations: this yields the so-called orbital degeneracy loci. A preferred class of those loci is characterized by a certain crepancy condition on the orbit closure, that allows to get control of the canonical sheaf. This condition is fulfilled for Richardson nilpotent orbits, or for partially decomposable skew-symmetric three-forms in six variables. This allows to construct new Fano fourfolds or Calabi-Yau threefolds and fourfolds. (Joint with V. Benedetti, S. Filippini, F. Tanturri)

Autores: Laurent, Manivel.