Date: 14 September 2018 Location: Hempfield High School, Room 213 Speaker: Linda Chen, Swarthmore College Title: Enumerative Geometry: Numbers and Beyond Abstract: Enumerative geometry problems have been studied by algebraic geometers since the nineteenth century. Indeed, enumeration was the subject of Hilbert’s Fifteenth problem. We will explore several enumerative problems and describe some underlying structures that encode the numbers. For example, a breakthrough in the 1990’s inspired by physics gave surprising and beautiful answers to classical problems, such as the enumeration of degree d rational plane curves passing through 3d-1 general points. I will also discuss extensions and open problems.