{ "id": "2106.14293", "version": "v1", "published": "2021-06-27T17:31:24.000Z", "updated": "2021-06-27T17:31:24.000Z", "title": "On determining the homological Conley index of Poincaré maps in autonomous systems", "authors": [ "Roman Srzednicki" ], "categories": [ "math.DS" ], "abstract": "A theorem on computation of the homological Conley index of an isolated invariant set of the Poincar\\'e map associated to a section in a rotating local dynamical system $\\phi$ is proved. Let $(N,L)$ be an index pair for a discretization $\\phi^h$ of $\\phi$, where $h>0$, and let $S$ denote the invariant part of $N\\setminus L$; it follows that the section $S_0$ of $S$ is an isolated invariant set of the Poincar\\'e map. The theorem asserts that if the sections $N_0$ of $N$ and $L_0$ of $L$ are ANRs, the homology classes $[u_j]$ of some cycles $u_j$ form a basis of $H(N_0,L_0)$, and for some scalars $a_{ij}$, the cycles $u_j$ and $\\sum a_{ij}u_i$ are homologous in the covering pair $(\\widetilde N,\\widetilde L)$ of $(N,L)$ and the homology relation is preserved in $(\\widetilde N,\\widetilde L)$ under the transformation induced by $\\phi^t$ for $t\\in [0,h]$ then the homological Conley index of $S_0$ is equal to the Leray reduction of the matrix $[a_{ij}]$. In particular, no information on the values of the Poincar\\'e map or its approximations is required. In a special case of the system generated by a $T$-periodic non-autonomous ordinary differential equation with rational $T/h>1$, the theorem was proved in the paper M.\\,Mrozek, R.\\,Srzednicki, and F.\\,Weilandt, SIAM J. Appl. Dyn. Syst. 14 (2015), 1348-1386, and it motivated a construction of an algorithm for determining the index.", "revisions": [ { "version": "v1", "updated": "2021-06-27T17:31:24.000Z" } ], "analyses": { "subjects": [ "37B30", "37B35" ], "keywords": [ "homological conley index", "autonomous systems", "poincare map", "isolated invariant set", "periodic non-autonomous ordinary differential equation" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }