Date: Friday, January 08, 2016
Location: 4088 East Hall (3:10 PM to 4:00 PM)
Title: Puzzles and equivariant Ktheory of Grassmannians
Abstract: The cohomology of the Grassmannian has a basis of Schubert classes. The structure constants for this basis, the celebrated LittlewoodRichardson coefficients, are calculated by any of the LittlewoodRichardson rules. This story has been extended to Ktheory by A. Buch (2002) and to torusequivariant cohomology by A. KnutsonT. Tao (2003). It is natural to unify these theories via a combinatorial rule for structure coefficients in equivariant Ktheory. In 2005, A. KnutsonR. Vakil used puzzles to conjecture such a rule. Recently we proved the first combinatorial rule for these coefficients. Using our new rule, we construct a counterexample to the KnutsonVakil conjecture and prove a mild correction to it. (Joint work with Alexander Yong)
Files:
Speaker: Oliver Pechenik
Institution: U. Illinois (UrbanaChampaign)
Event Organizer: Sergey Fomin
