Yannick Herfray (Tours) will give the geometry seminar at 2pm on 23rd Feb, in the Salle des Profs (9th floor building NO). Yannick’s title is “A new twist to twistor theory (higher spin interactions)” and his abstract is below.
It is notoriously difficult to write down non linear equations involving “higher spin fields”. In fact very few examples exists : On this very short list one finds “self-dual higher spin gravity” (Krasnov-Tung-Zkvortzov), for which higher spin fields couple non linearly to self-dual Einstein metrics. I will review these and present our last results with Noémie Parrini, Nicolas Boulanger and Lionel Mason relating these equations to twistor space geometry. As I will explain, it turns out that solutions of these equations have a natural interpretation as deformations of the complex structure of non projective twistor space. This suggests an extension of Penrose theorem (a.k.a Atiyah-Hitchin-Singer theorem in euclidean signature) in this context and, what is more, provides a notion higher spin geometries.