English

Smith-Gysin Sequence

Algebraic Topology 2025-02-06 v2 Differential Geometry

Abstract

Starting with a manifold MM and a semi-free action of S3S^3 on it, we have the Smith-Gysin sequence: H(M)H3(M/S3,MS3)H(MS3)H+1(M/S3,MS3)H+1(M) \cdots \to H^{*}( M) \to H^{*-3}(M/S^3, M^{S^3}) \oplus H^{*} (M^{S^3}) \to H^{*+1}(M/S^3, M^{S^3}) \to H^{*+1}(M) \to \cdots In this paper, we construct a Smith-Gysin sequence that does not require the semi-free condition. This sequence includes a new term, referred to as the "exotic term," which depends on the subset MS1M^{S^1}: H(M)H3(M/S3,Σ/S3)H(MS3)(H2(MS1))Z2H+1(M/S3,MS3)H+1(M) \cdots \to H^{*}(M) \to H^{*-3} (M/S^3, \Sigma/S^3) \oplus H^{*}(M^{S^3}) \oplus \left( H^{*-2}(M^{S^1})\right)^{-\mathbb{Z}_2} \to H^{*+1}(M/S^3,M^{S^3}) \to H^{*+1}(M) \to \cdots Here, ΣM\Sigma \subset M is the subset of points in MM whose isotropy groups are infinite. The group Z2\mathbb{Z}_2 acts on MS1M^{S^1} by jS3j \in S^3.

Cite

@article{arxiv.2310.04309,
  title  = {Smith-Gysin Sequence},
  author = {J. I. Royo Prieto and M. Saralegi Aranguren and R. Wolak},
  journal= {arXiv preprint arXiv:2310.04309},
  year   = {2025}
}

Comments

We have changed the abstrast, which was unreadable

R2 v1 2026-06-28T12:42:40.278Z