Seminari del Dipartimento

 

Geometria

Fano Congruences

Pietro De Poi


15-03-2018 - 14:30
Largo San Leonardo Murialdo,1 - Pal.C - AULA 211

 

We study congruences of lines of P^n (i.e. subvarieties of the Grassmannian of (co)dimension n-1) X defined by 3-forms, a class of congruences that are irreducible components of some reducible linear congruences, and their residual Y.
We prove that X, and its fundamental locus F if n is odd, are Fano varieties of index 3 and that X is smooth; F is smooth as well if n<10.
We study the Hilbert scheme of these congruences X, proving that the choice of the 3-form bijectively corresponds to X, except when n=5.
Y is analysed in terms of the quadrics containing the linear span of X and we determine the singularities and the irreducible components of its fundamental locus.
Joint work with Emilia Mezzetti, Daniele Faenzi and Kristian Ranestad.
org: VIVIANI Filippo