English

From mapping class groups to monoids of homology cobordisms: a survey

Geometric Topology 2015-03-13 v5

Abstract

Let S be a compact oriented surface. A homology cobordism of S is a cobordism C between two copies of S, such that both the "top" inclusion and the "bottom" inclusion of S in C induce isomorphisms in homology. Homology cobordisms of S form a monoid, into which the mapping class group of S embeds by the mapping cylinder construction. In this paper, we survey recent works on the structure of the monoid of homology cobordisms, and we outline their relations with the study of the mapping class group. We are mainly interested in the cases where the boundary of S is empty or connected.

Keywords

Cite

@article{arxiv.1003.2512,
  title  = {From mapping class groups to monoids of homology cobordisms: a survey},
  author = {Kazuo Habiro and Gwenael Massuyeau},
  journal= {arXiv preprint arXiv:1003.2512},
  year   = {2015}
}

Comments

54 pages. Minor modifications. To appear in the "Handbook of Teichm\"uller theory, volume III" (editor: A. Papadopoulos)