Emily Cliff (University of Sydney) Friday 23 August, 12-1pm, Place: Carslaw 375 Title: Chiral algebras, factorization algebras, and Borcherds’ "singular commutative rings" approach to vertex algebras. Abstract: In the late 1990s, Borcherds gave an alternate definition of some vertex algebras as "singular commutative rings" in a category of functors depending on some input data (A,H,S). He proved that for a certain choice of A, H, and S, the singular commutative rings he defines are indeed examples of vertex algebras. In this talk I will explain how we can vary this input data to produce categories of chiral algebras and factorization algebras (in the sense of Beilinson--Drinfeld) over certain complex curves X. We’ll discuss the failure of these constructions to give equivalences of categories. I will not assume background in vertex algebras, factorization algebras, or chiral algebras.