This is a report on joint work with H. Esnault and M. Schusterman.Recall that the étale fundamental group of a variety over an algebraically closed field of characteristic 0 is known to be a finitely presented profinite group; this is proved by…
Categoria evento: Algebraic and Arithmetic Geometry Seminar
The Heisenberg category of a category – Ádám Gyenge (Alfréd Rényi Institute of Mathematics)
The Heisenberg algebra associated with a lattice is a much-investigated object originating in quantum theory. Khovanov introducedrecently a categorification of the infinite Heisenberg algebraassociated with the free boson or, equivalently, a rank 1…
Hecke correspondences and Lagrangian fibrations – Sam DeHority (Columbia University)
I will discuss a method to associate new algebraic structures with deformations to certain holomorphic Lagrangian fibrations, and describe their relation with other parts of mathematical physics. This algebraic structure controls the enumerative…
Mirror symmetry for generalized Kummer varieties – Justin Sawon (University of North Carolina at Chapel Hill, USA)
The generalized Kummer variety $K_n$ of an abelian surface $A$ is the fibre of the natural map $\mathsf{Hilb}^{n+1}A\to \mathsf{Sym}^{n+1}A\to A$. Debarre described a Lagrangian fibration on $K_n$ whose fibres are the kernels of $\mathsf{Jac}C\to…
Geometry of vertex operator algebras on moduli of curves – Nicola Tarasca (Virginia Commonwealth University)
The physically-inspired theory of conformal blocks allows one to construct vector bundles on moduli spaces of curves with remarkable geometric and combinatorial properties. This theory uses as input the representations of some non-commutative…
Searching for the impossible Azumaya algebra – Siddharth Mathur (Orsay)
In two 1968 seminars, Grothendieck used the framework of etale cohomology to extend the definition of the Brauer group to all schemes. Over a field, the objects admit a well-known algebro-geometric description: they are represented by…
Two results about Grothendieck’s Section Conjecture – Giulio Bresciani (SNS Pisa)
Grothendieck’s Section Conjecture states that, if $X$ is an hyperbolic curve over a field $k$ finitely generated over $\mathbb{Q}$, every section of the map $\pi_1(X) \to \mathsf{Gal}(k)$ is associated with a rational point of the completion of $X$.…
Boundary divisors in the stable pair compactification of the moduli space of Horikawa surfaces – Luca Schaffler (Roma 3)
Smooth minimal surfaces of general type with $K^2=1$, $p_g=2$, and $q=0$ constitute a fundamental example in the geography of algebraic surfaces, and the 28-dimensional moduli space $M$ of their canonical models admits a geometric and modular…
Parabolicity conjecture of F-isocrystals – Marco D’Addezio (Université de Paris)
In the last years the theory of crystalline cohomology and F-isocrystals had a great development. I will present a new result concerning the algebraic monodromy groups of F-isocrystals. I will start with a quick introduction on crystalline…
Variation of stable birational type and bounds for complete intersections – Johannes Nicaise (KU Leuven and Imperial College London)
This talk is based on joint work with John Christian Ottem. I will explain a generalization of results by Shinder on variation of stable birational types in degenerating families, and how this can be used to extend Schreieder’s non-stable…