Geometry Seminar
University of Tor Vergata, Department of Mathematics
20th of February 2024, 14:30-16:00, room
“Dal Passo”
CM-minimizers
and standard models of Fano fibrations
over curves
Maksym Fedorchuk
Boston College
A recent achievement in K-stability of
Fano varieties is an
algebro-geometric construction
of a projective moduli space
of
K-polystable Fanos. The ample line bundle on this moduli space is the
CM line bundle of Tian. One
of the consequences of the general theory
is that given
a family of K-stable Fanos
over a punctured curve, the
polystable filling is the one that
minimizes the degree of the
CM line
bundle after every finite
base change. A natural question is to
ask what are the CM-minimizers without base change. In
answering this question, we arrive
at a theory of Kollár stability
for fibrations over one-dimensional
bases, and standard models
of Fano
fibrations. After explaining the general theory, I will sketch work in
progress on standard models of quartic
threefold hypersurfaces. This
talk is based on joint work
with Hamid Abban and Igor Krylov.
This
talk is part of the activity of the MIUR Excellence Department Projects MathMod@TOV, and the PRIN 2022 Moduli Spaces and Birational Geometry