INTERDISCIPLINARY STOCHASTIC PROCESSES COLLOQUIUM Tuesday October 16, room 60 Evans, 4.10 - 5.00pm Speaker: Richard Kenyon (Brown) Title: Branched polymers In this talk a "branched polymer" will be a connected collection of unit disks with non-overlapping interiors. Building on and from the work of Brydges and Imbrie, we give an elementary calculation of the volume of the space of branched polymers with $n$ disks in the plane and in 3-space. Our development reveals some more general identities, and allows exact random sampling. In particular we show that a random $3$-dimensional branched polymer with $n$ disks has diameter of order $\sqrt{n}$. [Joint work with Peter Winkler]