Table of Contents
Fetching ...

On Smooth Whitney Extensions of almost isometries with small distortion, Interpolation and Alignment in $\Bbb R^D$-Part 1

S. B. Damelin, C. Fefferman

Abstract

In this paper, we study the following problem: Let $D\geq 2$ and let $E\subset \mathbb R^D$ be finite satisfying certain conditions. Suppose that we are given a map $φ:E\to \mathbb R^D$ with $φ$ a small distortion on $E$. How can one decide whether $φ$ extends to a smooth small distortion $Φ:\mathbb R^D\to \mathbb R^D$ which agrees with $φ$ on $E$. We also ask how to decide if in addition $Φ$ can be approximated well by certain rigid and non-rigid motions from $\mathbb R^D\to \mathbb R^D$. Since $E$ is a finite set, this question is basic to interpolation and alignment of data in $\mathbb R^D$. The work in this paper appears in the research memoir [10].

On Smooth Whitney Extensions of almost isometries with small distortion, Interpolation and Alignment in $\Bbb R^D$-Part 1

Abstract

In this paper, we study the following problem: Let and let be finite satisfying certain conditions. Suppose that we are given a map with a small distortion on . How can one decide whether extends to a smooth small distortion which agrees with on . We also ask how to decide if in addition can be approximated well by certain rigid and non-rigid motions from . Since is a finite set, this question is basic to interpolation and alignment of data in . The work in this paper appears in the research memoir [10].

Paper Structure

This paper contains 14 sections, 10 theorems, 112 equations.

Key Result

Theorem 2.1

Given $\varepsilon>0$, there exists $\delta>0$ depending on $\varepsilon$ such that the following holds: Let $y_1,...y_k$ and $z_1,...z_k$ be two $1\leq k\leq D$ sets of distinct points in $\mathbb R^D$. Suppose that Then there exists a diffeomorphism (in particular 1-1 and onto) $\Phi:\mathbb R^D\to \mathbb R^D$ with satisfying

Theorems & Definitions (13)

  • Theorem 2.1
  • Theorem 2.2
  • Theorem 2.3
  • Theorem 2.4
  • Example 1
  • Example 2
  • Remark 3.5
  • Lemma 5.6
  • Lemma 5.7
  • Corollary 5.8
  • ...and 3 more