Hello and welcome to a new year of Algebra Seminars, with a new seminar organiser, Anne Thomas. I’d like to thank the previous organiser James East for his great work running the seminar and for his help getting me started. The series will officially resume in March, but next Wednesday 9 February we will have an early talk given by Bryan Wang from ANU. Title and abstract are below -- note the unusual day and venue. After the seminar we will take Bryan to lunch at the Grandstand Bar. So that I can give the Grandstand accurate numbers, please email me by Monday 7 February if you plan to attend the lunch. Finally, I am currently looking for speakers for March and April -- if you and/or any of your visitors would like to give a talk, I would be very happy to hear from you. --------------------------------------------------------------------- Speaker: Bryan Wang (Australian National University) Date: Wednesday 9 February Time: 12 noon Venue: Carslaw Room 535 Title: Stringy product on orbifold K-theory Abstract: Motivated by orbifold string theory models in physics, Chen and Ruan discovered a new product called the stringy product on the cohomology for the inertia orbifold of an almost complex orbifold. This cohomology with the stringy product is now called the Chen-Ruan cohomology, as a classical limit of orbifold quantum cohomology theory. Later, various versions of stringy product on orbifold K-theory of the inertia orbifold were proposed. In a recent joint work with Hu, we define a stringy product on the orbifold K-theory for the orbifold itself and show that a modified de-localized Chern character to the Chen-Ruan cohomology is an isomorphism over the complex coefficient. As an application, we find a new product on the equivariant K-theory of a finite group with the conjugation product, which is different to the well-known Pontryajin (or fusion) product. ---------------------------------------------------------------------