{ "id": "1606.08322", "version": "v1", "published": "2016-06-27T15:35:59.000Z", "updated": "2016-06-27T15:35:59.000Z", "title": "Zero sets of Lie algebras of analytic vector fields on real and complex 2-dimensional manifolds, II", "authors": [ "Morris W. Hirsch", "F. -J. Turiel" ], "categories": [ "math.DS" ], "abstract": "On a real ($\\mathbb F=\\mathbb R$) or complex ($\\mathbb F=\\mathbb C$) analytic connected 2-manifold $M$ with empty boundary consider two vector fields $X,Y$. We say that $Y$ {\\it tracks} $X$ if $[Y,X]=fX$ for some continuous function $f\\colon M\\rightarrow\\mathbb F$. Let $K$ be a compact subset of the zero set ${\\mathsf Z}(X)$ such that ${\\mathsf Z}(X)-K$ is closed, with nonzero Poincar\\'e-Hopf index (for example $K={\\mathsf Z}(X)$ when $M$ is compact and $\\chi(M)\\neq 0$) and let $\\mathcal G$ be a finite-dimensional Lie algebra of analytic vector fields on $M$. \\smallskip {\\bf Theorem.} Let $X$ be analytic and nontrivial. If every element of $\\mathcal G$ tracks $X$ and, in the complex case when ${\\mathsf i}_K (X)$ is positive and even no quotient of $\\mathcal G$ is isomorphic to ${\\mathfrak {s}}{\\mathfrak {l}} (2,\\mathbb C)$, then $\\mathcal G$ has some zero in $K$. \\smallskip {\\bf Corollary.} If $Y$ tracks a nontrivial vector field $X$, both of them analytic, then $Y$ vanishes somewhere in $K$. \\smallskip Besides fixed point theorems for certain types of transformation groups are proved. Several illustrative examples are given.", "revisions": [ { "version": "v1", "updated": "2016-06-27T15:35:59.000Z" } ], "analyses": { "subjects": [ "20F16", "58J20", "37F75", "37O25", "54H25" ], "keywords": [ "analytic vector fields", "zero set", "nonzero poincare-hopf index", "finite-dimensional lie algebra", "nontrivial vector field" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }