Contact type
# Contact type

In mathematics, more precisely in symplectic geometry, a hypersurface $\Sigma$ of a symplectic manifold $(M,\omega )$ is said to be of contact type if there is 1-form $\alpha$ such that $j^{*}(\omega )=d\alpha$ and $(\Sigma ,\alpha )$ is a contact manifold, where $j:\Sigma \to M$ is the natural inclusion. The terminology was first coined by Alan Weinstein.

