English

Periodicity of the pure mapping class group of non-orientable surfaces

Algebraic Topology 2023-08-03 v1 Geometric Topology

Abstract

We show that the pure mapping class group Ngk\mathcal{N}_{g}^{k} of a non-orientable closed surface of genus g2g\geqslant 2 with k1k\geqslant 1 marked points has pp-periodic cohomology for each odd prime pp for which Ngk\mathcal{N}_{g}^{k} has pp-torsion. Using the Yagita invariant and the cohomology classes obtained by the representation of subgroups of order pp, we obtain that the pp-period is less than or equal to 44 when g3g\geqslant 3 and k1k\geqslant 1. Moreover, combining the Nielsen realization theorem and a characterization of the pp-period given in terms of normalizers and centralizers of cyclic subgroups of order pp, we show that the pp-period of Ngk\mathcal{N}_{g}^{k} is bounded below by 44, whenever Ngk\mathcal{N}_{g}^{k} has pp-periodic cohomology, g3g\geqslant 3 and k0k\geqslant 0. These results provide partial answers to questions proposed by G. Hope and U. Tillmann.

Keywords

Cite

@article{arxiv.2308.01129,
  title  = {Periodicity of the pure mapping class group of non-orientable surfaces},
  author = {Nestor Colin and Rita Jiménez Rolland and Miguel A. Xicoténcatl},
  journal= {arXiv preprint arXiv:2308.01129},
  year   = {2023}
}

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16 pages