Topology Seminar: Constantine Medynets (US Naval Academy)

Krieger 205

Title:  Cantor Dynamical Systems, Bratteli Diagrams, and Their Associated Full GroupsAbstract:  If a countable group  G  acts on a Cantor set  X, one can enlarge  G  to a (still countable) group  F(G)  by adding homeomorphisms of  X  that act locally as elements of  G. This group, known as the full group of the dynamical system  […]

Topology Seminar: Julianne Rainbolt (Saint Louis University)

Krieger 205

Title:  A Comparison of Two Supercharacter TheoriesAbstract:  In 2008, P. Diaconis and I.M. Isaacs introduced a generalization of classical character theory, which they called supercharacter theory.  Let X be a partitioning of the irreducible characters of a finite group G such that the trivial character is in its own block of this partition.  Let Y […]

Topology Seminar: Arik Wilbert (University of South Alabama)

Krieger 205

Title: Two-row Delta Springer varietiesAbstract: I will discuss the geometry and topology of a certain family of so-called Delta Springer varieties from an explicit, diagrammatic point of view. These singular varieties were introduced by Griffin—Levinson—Woo in 2021 in order to give a geometric realization of an expression that appears in the t = 0 case of […]

Topology Seminar: Valentina Zapata Castro (University of Virginia)

Krieger 205

Title: Monoidal complete Segal spaces. Abstract: Viewing a monoid as a category with a single object allows us to encode the binary operation using the properties of composition and associativity inherent in any category. In this talk, we use this idea to explore the relationship between (∞,1)-categories with a monoidal structure and (∞,2)-categories with one […]

Topology Seminar: Bach Nguyen (Xavier University of Louisiana)

Krieger 205

Title:  Poisson geometry and Azumaya loci of cluster algebrasAbstract:  Roughly speaking, cluster algebra is a commutative algebra obtained from taking the intersection of Laurent polynomial rings associated a "seed". When a cluster algebra satisfies some compatibility condition, M. Gekhtman, M. Shapiro, and A. Vainshtein showed that one can connect a Poisson bracket to the cluster algebra. In […]

Topology Seminar (Postponed): Laurent Smits (Ruhr University Bochum)

Krieger 205

Title:  Spectral algebraic geometry and topological modular formsAbstract:  An important area of study in homotopy theory is the study of elliptic cohomology. In this talk we briefly review the context of elliptic cohomology and its interpretation in terms of spectral algebraic geometry. Furthermore, we construct the Deligne-Mumford compactification of the stack of oriented elliptic curves. If time […]

Topology Seminar: Thibaud van den Hove (Technical University of Darmstadt)

Zoom

Title:  Motives in geometric representation theoryAbstract:  The spherical and Iwahori-Hecke algebras of a reductive group are of great importance in the Langlands program. They are categorified by equivariant sheaves on the affine Grassmannian and affine flag variety respectively, as introduced in the previous talk. Similarly, the Satake and Bernstein isomorphisms are categorified by the Satake equivalence and […]