Contact quasi-states and their applications

Abstract

We introduce the notions of partial contact quasi-state and contact quasi-measure. Using the contact spectral invariant from the work by Djordjevi\'c-Uljarevi\'c-Zhang, one can construct partial contact quasi-states and contact quasi-measures on each contact manifold fillable by a Liouville domain with non-vanishing and $\mathbb{Z}$-graded symplectic homology. As an application, we present an alternative proof of the contact big fibre theorem from the recent work by Sun-Uljarevi\'c-Varolgunes under a mild topological condition. Our proof follows a more "classical" approach developed by Entov-Polterovich in the symplectic setting.