{ "id": "1702.07033", "version": "v1", "published": "2017-02-22T22:45:29.000Z", "updated": "2017-02-22T22:45:29.000Z", "title": "Length of a shortest closed geodesic in manifolds of dimension four", "authors": [ "Nan Wu", "Zhifei Zhu" ], "categories": [ "math.DG" ], "abstract": "In this paper, we show that for any closed 4-dimensional simply-connected Riemannian manifold $M$ with Ricci curvature $|Ric|>3$, volume $vol(M)>v>0$, and diameter $diam(M)