Workshop of Algebraic Geometry

   Seminario di Natale 2021 - December 20-21 2021


Program - December 20, 2021 (Aula Dottorato, first floor)

You can download the poster and the program.

14:00-14:50

Francesco Denisi

Boucksom-Zariski chambers, volumes, and Newton-Okounkov-type bodies on hyperkähler manifolds.

Abstract: In this talk I will provide for the big cone of a projective hyperkähler manifold a decomposition into chambers, in each of which the support of the negative part of the Boucksom-Zariski decomposition is constant. I will show how the obtained decomposition allows to determine the volume function. To conclude, time permitting, I will associate to any big divisor a 2-dimensional convex body, whose (euclidean) geometry is strictly related to both the volume and the variation in the big cone of the divisor itself.


15:00-15:50

Luca Giovenzana

Singularities of the perfect cone compactification

Abstract: The search for compactifications of moduli spaces is a central problem in algebraic geometry. Toroidal compactifications were constructed by Mumford to compactify moduli spaces that are locally symmetric varieties. In particular they define compactifications of the moduli space of polarised K3 surfaces with ADE singularities. After recalling the main properties of toroidal compactifications I will present some results about the singularities of a specific one, called perfect cone compactification.


16:30-17:20

Elisa Lorenzo Garcia

Reduction type of hyperelliptic curves in terms of the valuations of their invariants.

Abstract: In this talk we will first review the classical criteria to determine the (stable) reduction type of elliptic curves (Tate) and of genus 2 curves (Liu) in terms of the valuations of some particular combinations of their invariants. We will also revisit the theory of cluster pictures to determine the reduction type of hyperelliptic curves (Dokchitser's et al.). Via Mumford theta constants and Takase and Tomae's formulas we will be able to read the cluster picture information by looking at the valuations of some (à la Tsuyumine) invariants in the genus 3 case. We will also discuss the possible generalization of this strategy for any genus and some related open questions.






This event is supported by the reasearch project ERC-2017-CoG-771507, StabCondEn (web page).