Topological solitons in gravity

In this colloquium I will discuss aspects of microscopic degrees of freedom of gravity as motivated by string theory. Although these are expected to be generically quantum mechanical, our goal is to understand a class of such states that are coherent enough to admit classical descriptions in Einstein gravity. The construction of such states corresponds to adding interesting topological structures in spacetime with the help of compact extra dimensions. The constructions manifestly behave like ultra compact objects, dubbed topological stars, which can also model black hole microstates. I will discuss why it is interesting to understand such objects in a new age of gravitational waves astrophysics.

Recording (uw only).