Marine Fontaine (University of Antwerp) will speak in the geometry seminar on Tuesday 10 December 2019 at 11am in the Salle de Profs. Marine’s title is *Braids in the N-body problem by cabling a body in a central configuration* and her abstract is below.

*We prove the existence of periodic solutions of the N = n+1-body problem in an even dimensional Euclidean space: We start with n bodies whose reduced motion is close to a central configuration and we replace one of them by a pair of bodies rotating uniformly around their center of mass. When the motion takes place in the standard Euclidean plane these solutions are a special type of braid solutions. We use a variational formulation and the result is obtained by performing a Lyapunov-Schmidt reduction and the use of the Lyusternik-Schnirelmann category. This work is in collaboration with Carlos García-Azpeitia.*