Smooth Convergence Away From Singular Sets and Intrinsic Flat Continuity of Ricci Flow

Item

Title
Smooth Convergence Away From Singular Sets and Intrinsic Flat Continuity of Ricci Flow
Identifier
d_2009_2013:1521ca68c6e6:11798
identifier
12414
Creator
Lakzian, Sajjad,
Contributor
Chrisitina Sormani
Date
2013
Language
English
Publisher
City University of New York.
Subject
Mathematics | Applied mathematics | Forward Evolution | Intrinsic Flat | Neckpinch | Ricci Flow | Singularities | Smooth Convergence
Abstract
In this thesis we provide a framework for studying the smooth limits of Riemannian metrics away from singular sets. We also provide applications to the non-degenrate neckpinch singularities in Ricci flow. We prove that if a family of metrics, gi, on a compact Riemannian manifold, Mn, have a uniform lower Ricci curvature bound and converge to ginfinity smoothly away from a singular set, S, with Hausdorff measure, H n--1(S) = 0, and if there exists connected precompact exhaustion, Wj, of Mn \ S satisfying diamgi (Mn) ≤ D0 , Volgi (∂Wj) ≤ A 0 and Volgi (Mn \ Wj) ≤ Vj where limj→infinity Vj = 0 then the Gromov-Hausdorff limit exists and agrees with the metric completion of (Mn \ S, ginfinity). This is a strong improvement over prior work of the author with Sormani that had the additional assumption that the singular set had to be a smooth submanifold of codimension two. We have a second main theorem in which the Hausdorff measure condition on S is replaced by diameter estimates on the connected components of the boundary of the exhaustion, ∂Wj. This second theorem allows for singular sets which are open subregions of the manifold. In addition, we show that the uniform lower Ricci curvature bounds in these theorems can be replaced by the existence of a uniform linear contractibility function. If this condition is removed altogether, then we prove that lim j→infinity dFM'j ,N' = 0, in which M'j and N' are the settled completions of (M , gj) and (Minfinity \ S, ginfinity) respectively and dF is the Sormani-Wenger Intrinsic Flat distance. We present examples demonstrating the necessity of many of the hypotheses in our theorems.;In the second part of this thesis, we study the Angenent-Caputo-Knopf's Ricci Flow through neckpinch singularities. We will explain how one can see the A-C-K's Ricci flow through a neckpinch singularity as a flow of integral current spaces. We then prove the continuity of this weak flow with respect to the Sormani-Wenger Intrinsic Flat (SWIF) distance.
Type
dissertation
Source
2009_2013.csv
degree
Ph.D.
Program
Mathematics