14  18 June 2021, in Angers
The registration is open until 20 mai. To register, contact Susanna Zimmermann
Monday 14 June 
Tuesday 15 June 
Wednesday 16 June 
Thursday 17 June 
Friday 18 June 

9h4510h45 tba 11h12h tba 
9h4510h45 tba 11h12h tba 
9h4510h45 tba 11h12h tba 
9h4510h45 tba 11h12h tba 
14h1515h15 tba 15h3016h30 tba 16h4517h45 tba 
14h1515h15 tba 15h3016h30 tba 
14h1515h15 tba 15h3016h30 tba 
14h1515h15 tba 15h3016h30 tba 
Building L, Campus BelleBeille, Université d'Angers

On extension of pluricanonical forms defined on the central fiber of a Kähler family We will report on a recent joint work with M. Paun. We obtain an extension criterion for the canonical forms defined on an infinitesimal neighborhood of the central fiber of a family of Kähler manifolds. We will present some aspects of the proof of our main result, as well as its application to the extension of pluricanonical forms. title abstract On an effective YTD conjecture for multiplicity free manifolds The YTD conjecture relates the existence of constant scalar curvature Kähler metrics with an algebrogeometric condition called Kstability. The correct notion of Kstability to be used in this correspondence is not known precisely. An effective version of the YTD conjecture would be involving a Kstability condition that can be checked effectively on large families of examples. The resolution of the YTD conjecture for KählerEinstein metrics by Chen, Donaldson and Sun provided striking examples of this: in this case, the Kstability condition can be checked effectively for manifolds with a large group action such as multiplicity free manifolds or Tmanifolds of complexity one. In this talk, I will report on various recent advances and ongoing work on the YTD conjecture and more precisely on an effective YTD conjecture for cscK metrics on multiplicity free manifolds. title abstract title abstract A decomposition theorem for singular CalabiYau varieties Let $X$ be a compact Kähler manifold with trivial first Chern class. The BeauvilleBogomolov decomposition theorem (1984) asserts that there exists a finite unramified cover $X'\to X$ such that $X'$ is a product of a torus by irreducible varieties of two types (CalabiYau or holomorphic symplectic). The generalization of that statement to singular varieties arising from the Minimal Model Program was obtained in 2017 by HöringPeternell in the projective case, relying among other things on earlier works of Druel and GrebGuenanciaKebekus. In this talk, I will explain how to obtain the general Kähler case thanks to deformation theoretic arguments. This is joint work with Ben Bakker and Christian Lehn. title abstract BogomolovGuan manifolds The only known example of a nonKähler irreducible holomorphic symplectic manifold was described in works of Bogomolov and Guan. I am going to explain the construction and tell some results about the geometry of such manifolds. In particular, I will show that the algebraic reduction of a BGmanifold is isomorphic to a projective space and prove that the group of regular automorphisms of it is Jordan. It is a joint work with F. Bogomolov, N. Kurnosov and E. Yasinsky. Recent progress on the existence of minimal models In this talk I will present some recent progress on the existence of minimal models for varieties with mild singularities, as well as on the termination of flips in low dimensions. This progress is made possible by considering the category of generalised pairs, which appears naturally in several contexts. I will present joint work with Nikolaos Tsakanikas and touch upon recent works of ChenTsakanikas and Moraga. title abstract title abstract title abstract Rationality of Fano 3folds over nonclosed fields The rationality problem for smooth Fano threefolds over algebraically closed fields is basically solved. In this talk I will discuss rationality of forms of these Fanos over nonclosed fields of characteristic 0, as well as, rationality singular Fano 3folds with mild singularities. I will concentrate on the case where the Picard number equals 1. Part of the results are based on joint works with Alexander Kuznetsov. Generalised Kummer structures and moduli of generalised Kummer surfaces A generalised Kummer surface X is the resolution of the quotient of a complex 2torus A by an order 3 automorphism group G_A. If (B,G_B) is another complex 2torus such that the associated generalised Kummer surface is isomorphic to X, we say that (B,G_B) is a generalised Kummer structure on X. The aim of the talk will be to understand the number of these generalised Kummer structures, and the moduli space of these surfaces, when suitably polarised (in a certain sense when the surface is nonalgebraic). We will see that when X is algebraic or not the results are quite different. title abstract title abstract title abstract 
Ahmed Abouelsad (Basel)
Junyan Cao (Nice)
Livia Campo* (Warwick)
Paolo Cascini* (Imperial College)
Olivier de Gaay Fortman (ENS Paris)
Romaine Demelle (Poitiers)
Clara Dérand (Nancy)
Maria Gioia Cifani (Pavia)
Andrea Fanelli* (Bordeaux)
Enrica Floris (Poitiers)
Céline Gachet (Nice)
Maria Rosario GonzalezDorrego (UAM)
Henri Guenancia (Toulouse)
Liana Heuberger (Angers)
Alexandra Kusnetsova* (Moscow)
Stéphane Lamy (Toulouse)
Vlad Lazic* (Saarbrücken)
Anne Lonjou (Basel)
Irene Meunier (Toulouse)
John Christian Ottem* (Oslo)
Erik Paemurru (Basel)
Olga ParisRomaskevich* (Lyon)
Zolt Patakfalvi* (Lausanne)
MihaiCosmin Pavel (Lille)
Andrea Petracci* (Berlin)
Simone Pesatori (Roma Tre)
Renata Picciotto (Angers)
Elisa Postingel* (Trento)
Yuri Prokhorov* (Moscow)
Andriy Regeta* (Jena)
Xavier Roulleau (Marseille)
Julia Schneider (Toulouse)
Axel Supersac (Angers)
Dajano Tossici (Bordeaux)
Christian Urech (Lausanne)
Sridhar Venkatesh* (Michigan)
Egor Yasinsky (Basel)
Zhixin Xie (Nice)
Susanna Zimmermann (Angers)
Enrica Floris (Poitiers)
Susanna Zimmermann (Angers)
We gratefully acknowledge support from:
Projet Etoiles Montantes 2019
La Région Pays de la Loire
Université d'Angers