{ "id": "1205.5340", "version": "v1", "published": "2012-05-24T06:18:54.000Z", "updated": "2012-05-24T06:18:54.000Z", "title": "Homotopical rigidity of polygonal billiards", "authors": [ "Jozef Bobok", "Serge Troubetzkoy" ], "journal": "Topology and its Applications (2014) 308-324", "doi": "10.1016/j.topol.2014.06.003", "categories": [ "math.DS" ], "abstract": "Consider two $k$-gons $P$ and $Q$. We say that the billiard flows in $P$ and $Q$ are homotopically equivalent if the set of conjugacy classes in the fundamental group of $P$ which contain a periodic billiard orbit agrees with the analogous set for $Q$. We study this equivalence relationship and compare it to the equivalence relations, order equivalence and code equivalence, introduced in \\cite{BT1,BT2}. In particular we show if $P$ is a rational polygon, and $Q$ is homotopically equivalent to $P$, then $P$ and $Q$ are similar, or affinely similar if all sides of $P$ are vertical and horizontal.", "revisions": [ { "version": "v1", "updated": "2012-05-24T06:18:54.000Z" } ], "analyses": { "keywords": [ "polygonal billiards", "homotopical rigidity", "periodic billiard orbit agrees", "homotopically equivalent", "code equivalence" ], "tags": [ "journal article" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2012arXiv1205.5340B" } } }