{ "id": "2103.02836", "version": "v1", "published": "2021-03-04T05:12:14.000Z", "updated": "2021-03-04T05:12:14.000Z", "title": "Rigid reflections of rank 3 Coxeter groups and reduced roots of rank 2 Kac--Moody algebras", "authors": [ "Kyu-Hwan Lee", "Jeongwoo Yu" ], "comment": "31 pages", "categories": [ "math.RT" ], "abstract": "In a recent paper by K.-H. Lee and K. Lee, rigid reflections are defined for any Coxeter group via non-self-intersecting curves on a Riemann surface with labeled curves. When the Coxeter group arises from an acyclic quiver, the rigid reflections are related to the rigid representations of the quiver. For a family of rank $3$ Coxeter groups, it was conjectured in the same paper that there is a natural bijection from the set of reduced positive roots of a symmetric rank $2$ Kac--Moody algebra onto the set of rigid reflections of the corresponding rank $3$ Coxeter group. In this paper, we prove the conjecture.", "revisions": [ { "version": "v1", "updated": "2021-03-04T05:12:14.000Z" } ], "analyses": { "subjects": [ "16G20", "17B67", "20F55", "51F15" ], "keywords": [ "rigid reflections", "kac-moody algebra", "reduced roots", "coxeter group arises", "riemann surface" ], "note": { "typesetting": "TeX", "pages": 31, "language": "en", "license": "arXiv", "status": "editable" } } }