We introduce a chain complex associated to a Liouville domain pW , dλq whose boundary Y admits a Boothby-Wang contact form (i.e. is a prequantization space). The differential counts Floer cylinders with cascades in the completion W of W , in the spirit of Morse-Bott homology [Bou02,Fra04,BO09b]. The homology of this complex is the symplectic homology ofLet X be obtained from W by collapsing the boundary Y along Reeb orbits, giving a codimension 2 symplectic submanifold Σ. Under monotonicity assumptions on X and Σ, we show that for generic data, the differential in our chain complex counts elements of moduli spaces of cascades that are transverse. Furthermore, by some index estimates, we show that very few combinatorial types of cascades can appear in the differential.
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arXiv:1804.08013v2 [math.SG] 21 Nov 2018Definition 2.6. An admissible almost complex structure J X on X is compatible with ω and its restriction to ϕpUq is the push-forward by ϕ of a bundle almost complex structure on N Σ.An almost complex structure J W on pW, dλq is admissible if J W " ψ˚J X for an admissible J X . In particular, such almost complex structures are cylindrical and Reeb-invariant on W zW .A compatible almost complex structure J Y on the symplectization RˆY is admissible if J Y is cylindrical and Reeb-invariant.In the following, we will identify W with XzΣ by means of the diffeomorphism ψ and identify the corresponding almost complex structures. By an abuse of notation, 6 LUÍS DIOGO AND SAMUEL T. LISI we will both write π Σ : Y Ñ Σ to denote the quotient map that collapses the Reeb fibres, and π Σ : RˆY Ñ Σ to denote the composition of this projection with the projection to Y .Definition 2.7. Denote the space of almost complex structures in Σ that are compatible with ω Σ by J Σ .Let J Y denote the space of admissible almost complex structures on RˆY . Then, the projection dπ Σ induces a diffeomorphism between J Y and J Σ .Let J W denote the space of admissible almost complex structures on W . By Proposition 2.3, for any J W P J W , we obtain an almost complex structure J Σ .Denote this map by P : J W Ñ J Σ . This map is surjective and open by Proposition 2.3. For any given J Σ P J Σ , P´1pJ Σ q consist of almost complex structures on W that differ in W , or equivalently, can be identified (using ψ) with almost complex structures on X that differ in V " XzϕpUq.
The chain complexWe will now describe the chain complex for the split symplectic homology associated to W .