{ "id": "1809.10220", "version": "v1", "published": "2018-09-26T20:33:59.000Z", "updated": "2018-09-26T20:33:59.000Z", "title": "Nonnegative Ricci curvature, almost stability at infinity, and structure of fundamental groups", "authors": [ "Jiayin Pan" ], "categories": [ "math.DG" ], "abstract": "This is a continuation of the author's work arXiv:1710.05498. We study the fundamental group of an open $n$-manifold $M$ of nonnegative Ricci curvature with additional stability condition on $\\widetilde{M}$, the Riemannian universal cover of $M$. We show that if any tangent cone of $\\widetilde{M}$ at infinity is a metric cone, whose cross-section is sufficiently Gromov-Hausdorff close to a prior fixed metric space, then $\\pi_1(M)$ is finitely generated and contains a normal abelian subgroup of finite index; if in addition $\\widetilde{M}$ has Euclidean volume growth of constant at least $L$, then we can bound the index of that abelian subgroup in terms of $n$ and $L$. In particular, this result confirms the Milnor conjecture for any manifold whose universal cover has Euclidean volume growth of constant at least $1-\\epsilon(n)$, where $\\epsilon(n)>0$ is some universal constant.", "revisions": [ { "version": "v1", "updated": "2018-09-26T20:33:59.000Z" } ], "analyses": { "keywords": [ "nonnegative ricci curvature", "fundamental group", "euclidean volume growth", "riemannian universal cover", "additional stability condition" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }