17 jun 2024 - 21 jun 2024
Montréal, Canada
The scientific root of this workshop goes back to the seminal works of E. Calabi in the 1950s, who proposed to find a canonical Kähler metric, called extremal, representing a cohomology class of a compact Kähler manifold. Calabi showed that in this setting, the search for extremal Kähler metrics can be reduced to solving a non-linear PDE. A particular example of extremal Kähler metrics are the celebrated Kähler-Einstein metrics whose existence theory is now settled, starting with the resolution of Calabi’s famous conjecture by Aubin and Yau in the 1970s (the non-obstructed case), and culminating in recent times with the resolution of the Yau-Tian-Donaldson (YTD) conjecture in the obstructed Fano case. These efforts motivated a general YTD correspondence, which predicts that the existence of special Kähler metrics should be expressed in terms of a suitable complex-analytic / algebraic notion of stability of the underlying complex/projective variety.
Many partial results on such general YTD correspondences have been obtained recently in various special cases. For instance, the existence of a constant scalar curvature Kähler metric on a smooth toric variety is now settled whereas the log Fano case has been tackled recently, notably via weighted versions of Kähler-Ricci solitons. Another challenging direction of active current research consists of finding computable or even algorithmic criteria for algebraic stability (or for the existence of special Kähler metrics) on a given manifold, for example as in the recent works in the case of spherical varieties. Finally, the existence of special Kähler metrics or, equivalently, the corresponding stability notions, are expected to give the right tool for defining a good moduli space of polarized varieties.