{ "id": "2403.16322", "version": "v1", "published": "2024-03-24T23:06:50.000Z", "updated": "2024-03-24T23:06:50.000Z", "title": "On the mapping class group action on the homology of surface covers", "authors": [ "Igor Spiridonov" ], "comment": "11 pages, 2 figures", "categories": [ "math.GT" ], "abstract": "Let $\\phi \\in {\\rm Mod}(\\Sigma)$ be an arbitrary element of the mapping class group of a closed orientable surface $\\Sigma$ of genus at least $2$. For any characteristic cover $\\widetilde{\\Sigma} \\to \\Sigma$ one can consider the linear subspace ${\\rm H}_1^{f.o.}(\\widetilde{\\Sigma}, \\mathbb{Q})^\\phi \\subseteq {\\rm H}_1(\\widetilde{\\Sigma}, \\mathbb{Q})$ consisting of all homology classes with finite $\\phi$-orbit. We prove that $\\dim {\\rm H}_1^{f.o.}(\\widetilde{\\Sigma}, \\mathbb{Q})^\\phi$ can be arbitrary large for any fixed $\\phi \\in {\\rm Mod}(\\Sigma)$.", "revisions": [ { "version": "v1", "updated": "2024-03-24T23:06:50.000Z" } ], "analyses": { "subjects": [ "57K20", "57M10", "57M12" ], "keywords": [ "mapping class group action", "surface covers", "arbitrary element", "characteristic cover", "linear subspace" ], "note": { "typesetting": "TeX", "pages": 11, "language": "en", "license": "arXiv", "status": "editable" } } }