Title: Symmetries of Fano varieties.Abstract: A landmark result of Birkar, Prokhorov, and Shramov shows that automorphism groups of Fano (or more generally rationally connected) varieties over C of a fixed dimension are uniformly Jordan. This means in particular that there is some upper bound on the size of symmetric groups acting faithfully on rationally connected varieties of […]
Title: An introduction to Hopf Rings.Abstract: An old guy’s perspective on what homotopy theory used to be about and why complex cobordism has become central to the study.And, I’ll show one approach to getting more (and different) information about complex cobordism.If time permits (it won’t), I’ll show some of how chromatic homotopy theory comes out […]
Title: Dirac geometryAbstract: Whatever it is that animates anima and breathes life into higher algebra, this something gives the homotopy groups of a commutative algebra in spectra the structure of a commutative algebra in the symmetric monoidal category of graded abelian groups. Being commutative, these algebras form the affine building blocks of a geometry, which […]
Title: Elliptic curves and modular forms.Abstract: If you’ve heard of Fermat’s last theorem, you might have heard that its proof involves some sophisticated geometric objects that seemingly have nothing to do with whether a^n + b^n = c^n for n > 2. The objects in question are elliptic curves and modular forms. I will attempt […]
Title: Condensed abelian groups IAbstract: We will talk about the categories of κ-condensed abelian groups with Grothendieck axioms and why they are the abelian category of the nicest possible sort.
Title: Relative trace formulae and progress on the mixed truncationAbstract: After a quick (re)introduction to relative trace formulae, we shall focus on the divergence issue in establishing them. We plan to survey known examples of the mixed truncation and discuss an ongoing work on trace formulae for infinitesimal symmetric spaces.
Title: Skein theory and the geometric Langlands program.Abstract: Skein modules are certain families of vector spaces spanned by embedded links or graphs in a 3-manifold M, modulo certain local relations. They can be thought of both as an obstruction to defining a polynomial invariant of knots in M and as an invariant of the 3-manifold […]
Title: On the existence of isoperimetric sets on nonnegatively curved spaces Abstract: In this presentation, I will deal with the isoperimetric properties of spaces with nonnegative curvature, placing special emphasis on the existence of isoperimetric sets in the non-compact case. Isoperimetric sets of any volume do exist in compact Riemannian manifolds. Conversely, it is possible to construct simple examples […]
Title: On Fano and Calabi-Yau pairs of small coregularity.Abstract: The coregularity is an invariant that measures a specific type of combinatorial complexity of a pair. We will start this talk by defining this invariant and giving some examples. Then, we will explain how results about complements of Fano varieties of bounded dimension are still valid for Fano […]
Title: Degenerate, Generalized, and Reduced Whittaker models Abstract: Whittaker models are realizations of representations on a space of functions that transform in a certain way under the action of a unipotent group, and they have been central in both the local representation theory and the global theory of automorphic representations. For groups other than GL_n, […]
Title: Coherence theorems in the style of Mac LaneAbstract: The aim is to discuss different equational structures defined on categories like monoidal, symmetric monoidal and cartesian monoidal structures. The aim is to shed light on the associated coherence theorems and to show how these are related to the construction of simple type theories. This suggests a more general approach […]