## Enumerative Geometry Beyond Numbers

**Date:**
16 January - 25 May 2018

**Location: ** MSRI

**Event type:**
Extended Format

**Organisers: ** Mina Aganagic (Berkeley), Denis Auroux (Berkeley), Jim Bryan (British Columbia), Andrei Okounkov (Columbia), Balazs Szendroi (Oxford)

**Website:**www.msri.org/programs/295

Traditional enumerative geometry asks certain questions to which the expected answer is a number: for instance, the number of lines incident with two points in the plane (1, Euclid), or the number of twisted cubic curves on a quintic threefold (317 206 375). It has however been recognized for some time that the numerics is often just the tip of the iceberg: a deeper exploration reveals interesting geometric, topological, representation-, or knot-theoretic structures. This semester-long program will be devoted to these hidden structures behind enumerative invariants, concentrating on the core fields where these questions start: algebraic and symplectic geometry.

Professor **Hiraku Nakajima** (Kyoto) has been appointed as a Clay Senior Scholar to participate in this program.