The seminar deals with topics related to gravitation and geometry, including the following:

1) Gravitational Instantons - four-dimensional, complete, Ricci flat manifolds with at least quadratic curvature decay. There are several families of instantons, which all have special geometry. Solution generating techniques, including the Belinski-Zakharov soliton method, play an important role in constructing instantons. There are several uniqueness conjectures for instantons that remain open.

2) Solitons - localized steady states of field theories. There is a zoo of examples, in general relativity (eg. black holes, i.e. Lorentzian versions of gravitational instantons), wave equations (eg. Q Balls), Maxwell-Dirac theory, to name just a few. Surprisingly little is known about the stability and dynamics of these objects in 3+1 dimensions.