{ "id": "1911.12803", "version": "v1", "published": "2019-11-28T17:35:04.000Z", "updated": "2019-11-28T17:35:04.000Z", "title": "Separatrices for real analytic vector fields in the plane", "authors": [ "Eduardo Cabrera", "Rogério Mol" ], "comment": "16 pages", "categories": [ "math.DS", "math.CA", "math.CV" ], "abstract": "Let $X$ be a germ of real analytic vector field at $({\\mathbb R}^{2},0)$ with an algebracally isolated singularity. We say that $X$ is a topological generalized curve if there are no topological saddle-nodes in its reduction of singularities. In this case, we prove that if either the order $\\nu_{0}(X)$ or the Milnor number $\\mu_{0}(X)$ is even, then $X$ has a formal separatrix, that is, a formal invariant curve at $0 \\in {\\mathbb R}^{2}$. This result is optimal, in the sense that these hypotheses do not assure the existence of a convergent separatrix.", "revisions": [ { "version": "v1", "updated": "2019-11-28T17:35:04.000Z" } ], "analyses": { "subjects": [ "32S65", "37F75", "34Cxx", "14P15" ], "keywords": [ "real analytic vector field", "formal invariant curve", "singularity", "formal separatrix", "milnor number" ], "note": { "typesetting": "TeX", "pages": 16, "language": "en", "license": "arXiv", "status": "editable" } } }