Markus Pflaum (University of Colorado, Boulder) Introduction to Lie groupoids from a geometric point of view
Apr. 23, 2019 1pm (MATH 220)
Grad Algebra/Logic
Keith Kearnes (CU) Congruence n-permutability is not join prime, 2
Apr. 23, 2019 2pm (MATH 220)
Agnes Szendrei (CU Boulder) Flexible Ultrafilters and the Theory of the Random Graph, Part 2
Apr. 23, 2019 2pm (MATH 350)
Lie Theory
Nathan Lindzey (CU)
X
We discuss a Hecke algebra associated with the permutation representation of the symmetric group acting on the set of matchings of the complete graph. This permutation representation is reminiscent of a more complicated representation that arises when deciding the semi-simplicity of Brauer algebras (see Hanlon & Wales), but our motivation comes from optimization, namely, symmetric semidefinite relaxations of the perfect matching problem. Realizing this Hecke algebra as a non-commutative matrix algebra, we give combinatorial formulas for many of the eigenvalues of operators in this algebra. This is joint work in progress with Gary Au and Levent Tunçel.
Harmonic Analysis on Matchings