{ "id": "2406.07509", "version": "v1", "published": "2024-06-11T17:43:18.000Z", "updated": "2024-06-11T17:43:18.000Z", "title": "Uniqueness on average of large isoperimetric sets in noncompact manifolds with nonnegative Ricci curvature", "authors": [ "Gioacchino Antonelli", "Marco Pozzetta", "Daniele Semola" ], "comment": "40 pages. Comments welcome!", "categories": [ "math.DG", "math.MG" ], "abstract": "Let $(M^n,g)$ be a complete Riemannian manifold which is not isometric to $\\mathbb{R}^n$, has nonnegative Ricci curvature, Euclidean volume growth, and quadratic Riemann curvature decay. We prove that there is a set $\\mathcal{G}\\subset (0,\\infty)$ with density $1$ at infinity such that for every $V\\in \\mathcal{G}$ there is a unique isoperimetric set of volume $V$ in $M$, and its boundary is strictly volume preserving stable. The latter result cannot be improved to uniqueness or strict stability for every large volume. Indeed, we construct a complete Riemannian surface that satisfies the previous assumptions, and with the following property: there are arbitrarily large and diverging intervals $I_n\\subset (0,\\infty)$ such that isoperimetric sets with volumes $V\\in I_n$ exist, but they are neither unique nor they have strictly volume preserving stable boundaries. The proof relies on a set of new ideas, as the present setting goes beyond the range of applicability of the methods based on the implicit function theorem, and no symmetry is assumed.", "revisions": [ { "version": "v1", "updated": "2024-06-11T17:43:18.000Z" } ], "analyses": { "keywords": [ "nonnegative ricci curvature", "large isoperimetric sets", "noncompact manifolds", "volume preserving stable boundaries", "uniqueness" ], "note": { "typesetting": "TeX", "pages": 40, "language": "en", "license": "arXiv", "status": "editable" } } }