### Pretty Good Gravity, by Jack Morava

A theory of topological gravity is a homotopy-theoretic
representation of the Segal-Tillmann topologification of a two-category
with cobordisms as morphisms. This note describes a relatively accessible
example of such a thing, suggested by the wall-crossing formulas of
Donaldson theory.

[This is a writeup of a talk at the RIMS Symposium on algebraic geometry
and integrable systems related to string theory, June 12-16, 2000.]

Jack Morava <jack@math.jhu.edu>