{ "id": "2309.07829", "version": "v1", "published": "2023-09-14T16:19:20.000Z", "updated": "2023-09-14T16:19:20.000Z", "title": "Minimality of the $\\mathcal D$-groupoid of symmetries of a projective structure", "authors": [ "Alejandro Arenas Tirado", "David Blázquez-Sanz", "Guy Casale" ], "comment": "16 pages", "categories": [ "math.AG", "math.DG", "math.LO" ], "abstract": "In this article we study Kummer's $\\mathcal D$-groupoid, which is the groupoid of symmetries of a meromorphic projective structure. We give necessary and sufficient conditions for its minimality, in the sense of not having infinite sub-$\\mathcal D$-groupoids. The condition that we find turns out to be equivalent to the strong minimality of the non-linear Schwarzian equation and the non-integrability by means of Liouvillian functions of the linear Schwarzian equation.", "revisions": [ { "version": "v1", "updated": "2023-09-14T16:19:20.000Z" } ], "analyses": { "subjects": [ "34M15", "03C50" ], "keywords": [ "symmetries", "non-linear schwarzian equation", "strong minimality", "sufficient conditions", "study kummers" ], "note": { "typesetting": "TeX", "pages": 16, "language": "en", "license": "arXiv", "status": "editable" } } }