Search

Algebraic Geometry Algebra/Logic DeLong Diversity Functional Analysis Grad Algebra/Logic Init Conditions Kempner Lie Theory Math Club Math Phys Noncomm Geometry Number Theory PDE/Analysis Probability Rep Theory Grad Student Seminar Thesis Defenses Topology Ulam Math Edu

Events happening on April 2, 2024

Return to this week

Print these events

Apr. 02, 2024 1:25pm (online)	Algebra/Logic Will Brian (University of North Carolina at Charlotte) View Online:https://cuboulder.zoom.us/j/96896272260 X I'm going to talk about an old question of van Douwen: Are the shift map and its inverse conjugate in the automorphism group of P()/fin? By the late 1980's, van Douwen and Shelah proved that it is consistent they are not conjugate. Specifically, any automorphism witnessing their conjugacy would need to be nontrivial (van Douwen), but it is consistent that all automorphisms are trivial (Shelah). In this talk I'm going to discuss the recently-proven complementary result: it is consistent that the shift map and its inverse are conjugate and, in fact, it follows from CH. Does P()/fin know its right hand from its left?
Apr. 02, 2024 2:30pm (MATH 3…	Lie Theory Carl Mautner (UC Riverside) X The Schur algebra is a finite-dimensional algebra that relates the representation theory of symmetric and general linear groups. In joint work with Tom Braden we introduce a new algebra we call the Hilbert Schur algebra, which is also finite-dimensional and has the Schur algebra as a quotient. I will describe this algebra, our motivation for defining it, and some of its interesting algebraic and combinatorial properties. Hilbert Schur algebras Sponsored by the Meyer Fund
Apr. 02, 2024 3:30pm (MATH 3…	Topology Emily Montelius View Online:https://cuboulder.zoom.us/j/93245421661 X Together we will watch and discuss some introductory and overview materials covering knot theory from a graduate topology level An introduction to knot theory
Apr. 02, 2024 10:10pm (MATH …	Functional Analysis Rufus Willett (University of Hawaii) X The HK conjecture predicts an isomorphism between the homology of certain groupoids, and the K-theory of their C-algebras. On the other hand, the Baum-Connes conjecture predicts a topological computation of the K-theory of groupoid C-algebras. Both conjectures are wrong: there are counterexamples to the HK conjecture due to Scarparo, Deeley, Ortega-Scarparo, and Chaiser; and to the Baum-Connes conjecture due to Higson-Lafforgue-Skandalis. I will explain some interactions between these two conjectures, in particular focusing on the precise sense in which Baum-Connes predicts that HK is wrong, and how one might try to fix these issues. I will not assume any prior knowledge of the HK or Baum-Connes conjecture, and will focus on the case of group actions rather than general groupoids (for simplicity). Some of this is based on joint work with Christian Bönicke, Clément Dell'Aiera, and Jamie Gabe; some on joint work with Robin Deeley; and some on work of Valerio Proietti and Makoto Yamashita (that I had nothing to do with). The HK and Baum-Connes conjectures Sponsored by the National Science Foundation

Return to the top of the page