{ "id": "1903.01753", "version": "v1", "published": "2019-03-05T09:58:51.000Z", "updated": "2019-03-05T09:58:51.000Z", "title": "Deformations of smooth functions on $2$-torus", "authors": [ "Bohdan Feshchenko" ], "comment": "15 pages", "categories": [ "math.GT" ], "abstract": "Let $f $ be a Morse function on a smooth compact surface $M$ and $\\mathcal{S}'(f)$ be a group of $f$-preserving diffeomorphisms of $M$ which are isotopic to the identity map. Let also $G(f)$ be a group of automorphisms of the graph of $f$ induced by elements from $\\mathcal{S}'(f)$, and $\\Delta'$ be a subgroup of $\\mathcal{S}'(f)$ of diffeomorphisms which trivially act on the graph of $f$ and are isotopic to the identity map. The group $\\pi_0\\mathcal{S}'(f)$ can be viewed as an analogue of a mapping class group for $f$-preserved diffeomorphisms of $M$. Groups $\\pi_0\\Delta'(f)$ and $G(f)$ can be viewed as groups which encode `combinatorially trivial' and `combinatorially nontrivial' counterparts of $\\pi_0\\mathcal{S}'(f)$ respectively. In the paper we compute groups $\\pi_0\\mathcal{S}'(f)$, $G(f)$, and $\\pi_0\\Delta'(f)$ for Morse functions on $2$-torus $T^2$.", "revisions": [ { "version": "v1", "updated": "2019-03-05T09:58:51.000Z" } ], "analyses": { "subjects": [ "57S05", "20E22", "58B05" ], "keywords": [ "smooth functions", "deformations", "identity map", "morse function", "diffeomorphisms" ], "note": { "typesetting": "TeX", "pages": 15, "language": "en", "license": "arXiv", "status": "editable" } } }