{ "id": "1306.4458", "version": "v2", "published": "2013-06-19T09:03:49.000Z", "updated": "2015-03-26T14:46:05.000Z", "title": "Stable CMC and index one minimal surfaces in conformally flat manifolds", "authors": [ "Rabah Souam" ], "comment": "corrected version", "categories": [ "math.DG" ], "abstract": "Let $M$ be a Riemannian 3-manifold of nonnegative Ricci curvature, Ric $\\geq 0.$ We suppose that $M$ is conformally flat and simply connected or more generally that it admits a conformal immersion into the standard 3-sphere. Let $\\Sigma$ be a compact connected and orientable surface immersed in $M$ which is a stable constant mean curvature (CMC) surface or an index one minimal surface. We prove that $\\Sigma$ is homeomorphic either to a sphere or to a torus. Moreover, in case $\\Sigma$ is homeomorphic to a torus, then it is embedded, minimal, conformal to a flat square torus and Ric$(N)=0$ where $N$ is a unit field normal to $\\Sigma.$ The result is sharp, we can perturb the standard metric on the 3-sphere in its conformal class to obtain metrics of nonnegative Ricci curvature admitting minimal tori which are stable as CMC surfaces. As a consequence, in any 3-sphere of positive Ricci curvature which is conformally flat, the isoperimetric domains are topologically 3-balls. This proves a special case of a conjecture of A. Ros.", "revisions": [ { "version": "v1", "updated": "2013-06-19T09:03:49.000Z", "abstract": "Let $M$ be a Riemannian 3-manifold of nonnegative Ricci curvature, Ric $\\geq 0.$ We suppose that $M$ is conformally flat and simply connected or more generally that it admits a conformal immersion into the standard 3-sphere. Let $\\Sigma$ be a compact connected and orientable surface immersed in $M$ which is a stable constant mean curvature (CMC) surface or an index one minimal surface. We prove that $\\Sigma$ is homeomorphic either to a sphere or to a torus. Moreover, in case $\\Sigma$ is homeomorphic to a torus, then it is embedded, minimal, conformal to a flat square torus and Ric$(N)=0$ where $N$ is a unit field normal to $\\Sigma.$ The result is sharp, we can perturb the standard metric on the 3-sphere in its conformal class to obtain metrics of nonnegative Ricci curvature admitting minimal tori which are stable as CMC surfaces. As a consequence, in any 3-sphere of positive Ricci curvature which is conformally flat, the isoperimetric domains are topologically 3-balls.", "comment": null, "journal": null, "doi": null }, { "version": "v2", "updated": "2015-03-26T14:46:05.000Z" } ], "analyses": { "keywords": [ "conformally flat manifolds", "minimal surface", "stable cmc", "nonnegative ricci curvature", "ricci curvature admitting minimal tori" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2013arXiv1306.4458S" } } }