On the strict Arnold chord property and coisotropic submanifolds of complex projective space

Abstract

Let $α$ be a contact form on a manifold $M$, and $L\subseteq M$ a closed Legendrian submanifold. I prove that $L$ intersects some characteristic for $α$ at least twice if all characteristics are closed and of the same period, and $α$ embeds nicely into the product of $\mathbb{R}^{2n}$ and an exact symplectic manifold. As an application of the method of proof, the minimal action of a regular closed coisotropic submanifold of complex projective space is at most $π/2$. This yields an obstruction to presymplectic embeddings, and in particular to Lagrangian embeddings.