English

Sasaki structures distinguished by their basic Hodge numbers

Differential Geometry 2023-01-03 v2 Algebraic Geometry Geometric Topology Symplectic Geometry

Abstract

In all odd dimensions 5\geq 5 we produce examples of manifolds admitting pairs of Sasaki structures with different basic Hodge numbers. In dimension 55 we prove more precise results, for example we show that on connected sums of copies of S2×S3S^2\times S^3 the number of Sasaki structures with different basic Hodge numbers within a fixed homotopy class of almost contact structures is unbounded. All the Sasaki structures we consider are negative in the sense that the basic first Chern class is represented by a negative definite form of type (1,1)(1,1). We also discuss the relation of these results to contact topology.

Keywords

Cite

@article{arxiv.2110.03328,
  title  = {Sasaki structures distinguished by their basic Hodge numbers},
  author = {D. Kotschick and G. Placini},
  journal= {arXiv preprint arXiv:2110.03328},
  year   = {2023}
}

Comments

final version, to appear in Bull. London Math. Society

R2 v1 2026-06-24T06:41:58.322Z