{ "id": "2011.00295", "version": "v1", "published": "2020-10-31T15:40:52.000Z", "updated": "2020-10-31T15:40:52.000Z", "title": "On spectral sequence for the action of genus 3 Torelli group on the complex of cycles", "authors": [ "Alexander A. Gaifullin" ], "comment": "53 pages", "categories": [ "math.GT", "math.AT", "math.GR" ], "abstract": "The Torelli group of a genus $g$ oriented surface $S_g$ is the subgroup $\\mathcal{I}_g$ of the mapping class group $\\mathrm{Mod}(S_g)$ consisting of all mapping classes that act trivially on the homology of $S_g$. One of the most intriguing open problems concerning Torelli groups is the question of whether the group $\\mathcal{I}_3$ is finitely presented or not. A possible approach to this problem relies upon the study of the second homology group of $\\mathcal{I}_3$ using the spectral sequence $E^r_{p,q}$ for the action of $\\mathcal{I}_3$ on the complex of cycles. In this paper we obtain a partial result towards the conjecture that $H_2(\\mathcal{I}_3;\\mathbb{Z})$ is not finitely generated and hence $\\mathcal{I}_3$ is not finitely presented. Namely, we prove that the term $E^3_{0,2}$ of the spectral sequence is infinitely generated, that is, the group $E^1_{0,2}$ remains infinitely generated after taking quotients by images of the differentials $d^1$ and $d^2$. If one proceeded with the proof that it also remains infinitely generated after taking quotient by the image of $d^3$, he would complete the proof of the fact that $\\mathcal{I}_3$ is not finitely presented.", "revisions": [ { "version": "v1", "updated": "2020-10-31T15:40:52.000Z" } ], "analyses": { "subjects": [ "20F34", "57M07", "20J05" ], "keywords": [ "spectral sequence", "open problems concerning torelli groups", "intriguing open problems concerning torelli", "mapping class", "second homology group" ], "note": { "typesetting": "TeX", "pages": 53, "language": "en", "license": "arXiv", "status": "editable" } } }