标题： 三维黎曼流中的局部夹逼估计 显示英文标题

标题： Local pinching estimates in 3-dim Ricci flow

摘要： 我们研究在无有界曲率假设的完整3维流形上的Ricci流的曲率夹逼估计。 我们将推导一些一般的曲率条件，这些条件在任何完整的3维Ricci流解上都被保留，这些条件包括非负Ricci曲率和截面曲率作为特例。 还获得了Hamilton-Ivey估计的一个局部版本。 显示英文摘要

摘要： We study curvature pinching estimates of Ricci flow on complete 3- dimensional manifolds without bounded curvature assumption. We will derive some general curvature conditions which are preserved on any complete solution of 3-dim Ricci flow, these conditions include nonnegative Ricci curvature and sectional curvature as special cases. A local version of Hamilton-Ivey estimates is also obtained.