Laurence Mayther (Cambridge) will talk in the geometry seminar on 27th November, at 2pm in the Salle des Profs. Laurence’s title is *“New h-Principles in [split]G2, Symplectic and Contact Geometry” *and his abstract is below.

*An exterior form is termed stable if its algebraic properties are preserved by all sufficiently small perturbations. Stable forms are fundamental to the study of G2/[split]G2 geometry and symplectic geometry, and also play a key role in the study of contact geometry.*

I*n this talk, I shall introduce a new, general method for proving h-principles for stable forms, building on Gromov’s technique of convex integration, and use this to prove 4 new h-principles related to these geometries. Applications to the non-constructability of compact [split]G2 and symplectic manifolds via geometric flows will then be discussed. Time permitting, I shall also explain how this new method for proving h-principles subsumes all similar, previously established h-principles, and explain how it may be extended to prove a fifth new h-principle in 6-dimensions related to para-complex structures.*