{ "id": "2203.09805", "version": "v1", "published": "2022-03-18T09:11:04.000Z", "updated": "2022-03-18T09:11:04.000Z", "title": "Stability Indices of Non-Hyperbolic Equilibria", "authors": [ "Alexander Lohse" ], "categories": [ "math.DS" ], "abstract": "We consider families of systems of two-dimensional ordinary differential equations with the origin $0$ as a non-hyperbolic equilibrium. For any number $a \\in (-\\infty, +\\infty)$ we show that it is possible to choose a parameter in these equations such that the stability index $\\sigma(0)$ is precisely $\\sigma(0)=a$. In contrast to that, for a hyperbolic equilibrium $x$ it is known that either $\\sigma(x)=-\\infty$ or $\\sigma(x)=+\\infty$. Furthermore, we discuss a system with an equilibrium that is locally unstable but seems to be globally attracting, highlighting some subtle differences between the local and non-local stability indices.", "revisions": [ { "version": "v1", "updated": "2022-03-18T09:11:04.000Z" } ], "analyses": { "keywords": [ "stability index", "non-hyperbolic equilibrium", "two-dimensional ordinary differential equations", "non-local stability indices", "subtle differences" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }