English

Lower bound on the number of fixed points for circle actions on 10-dimensional almost complex manifolds

Algebraic Topology 2026-02-03 v2 Differential Geometry

Abstract

For a circle action on a compact almost complex manifold with a fixed point, the lower bound on the number of fixed points is known in dimension up to 12 except 10. In this paper, we show that if the circle group acts on a 10-dimensional compact almost complex manifold with a fixed point, then there are at least 6 fixed points. This minimum is attained by CP5\mathbb{CP}^5 and S6×CP2S^6 \times \mathbb{CP}^2. We establish this lower bound by showing that there does not exist a circle action on a 10-dimensional compact almost complex manifold with 4 fixed points.

Keywords

Cite

@article{arxiv.2411.03242,
  title  = {Lower bound on the number of fixed points for circle actions on 10-dimensional almost complex manifolds},
  author = {Donghoon Jang},
  journal= {arXiv preprint arXiv:2411.03242},
  year   = {2026}
}

Comments

corrected and simplified proof