Equivariant homology for generating functions and orderability of lens spaces

Abstract

In her PhD thesis, Milin developed a $Z_k$-equivariant version of the contact homology groups constructed in Geometry of contact transformations and domains: orderability vs squeezing, "Geom. Topol." 10 (2006), 1635–1747 and used it to prove a $Z_k$-equivariant contact non-squeezing theorem. In this article, we re-obtain the same result in the setting of generating functions, starting from the homology groups studied in Contact homology, capacity and non-squeezing in $R^2n × S^1$ via generating functions, "Ann. Inst. Fourier (Grenoble)" 61 (2011), 145–185. As Milin showed, this result implies orderability of lens spaces.