{ "id": "2205.08825", "version": "v1", "published": "2022-05-18T09:42:57.000Z", "updated": "2022-05-18T09:42:57.000Z", "title": "Certain invariant algebraic sets in $S^p \\times S^q$", "authors": [ "Joji Benny", "Soumen Sarkar" ], "categories": [ "math.DS", "math.CA" ], "abstract": "Let $S_{p,q}$ be the hypersurface in $\\mathbb{R}^{p+q+1}$ defined by the following: $$ S_{p,q} := \\left\\lbrace (x_1,\\ldots,x_{p+1},y_1,\\ldots,y_q) \\in \\mathbb{R}^{p+q+1} \\big| \\left( \\sum_{i=1}^{p+1} x_i^2 - a^2 \\right)^2 + \\sum_{j=1}^q y_j^2 = 1 \\right\\rbrace,$$ where $a > 1$. We show that $S_{p,q}$ is homeomorphic to the product $S^p \\times S^q$. We consider the polynomial vector field $\\mathcal{X} = (P_1,...,P_{p+1},Q_1,...,Q_q)$ in $\\mathbb{R}^{p+q+1}$ which keeps $S_{p,q}$ invariant. Then we study the number of certain invariant algebraic subvarieties of $S_{p,q}$ for the vector field $\\mathcal{X}$ if either $p>1$ or $q>1$.", "revisions": [ { "version": "v1", "updated": "2022-05-18T09:42:57.000Z" } ], "analyses": { "subjects": [ "34A34", "34C14", "34C40", "34C45", "58J90" ], "keywords": [ "invariant algebraic sets", "invariant algebraic subvarieties", "polynomial vector field", "homeomorphic", "hypersurface" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }