# Uniform Fat Segment and Cusp Properties for Compactness in Shape Optimization

Uniform Fat Segment and Cusp Properties for Compactness in Shape Optimization A general compactness theorem for shape/geometric analysis and optimization is given for a family of subsets verifying the uniform fat segment property in a bounded open holdall with or without constraints on the De Giorgi (11) or the γ-density perimeter of Bucur and Zolesio (3). The uniform fat segment property is shown to be equivalent to the uniform cusp property introduced in (9) with a continuous non-negative cusp function. This equivalence remains true for cusp functions that are only continuous at the origin. The equivalence of sets verifying a segment property with their C 0 -graph representation is further sharpened for sets with a compact boundary. Our C 0 -graph characterization is shown to be equivalent to both the uniform cusp property and the uniform segment property. It is used to formulate sufficient conditions on the local graphs of a family of subsets of a bounded open holdall to get compactness. A first condition assumes that the local graphs are bounded above by a cusp function; a second condition which requires that the local graphs be equicontinuous turns out to be equivalent to the first one. The respective solutions of the Laplacian with homogeneous Dirichlet or Neumann boundary condition are shown to be continuous with respect to domains in that family. In the Dirichlet case for 1 < p < ∞, we prove the (1,p)-stability of compact sets in the sense of Herdberg (14) under the weaker almost everywhere assumption rather than quasi everywhere. It is also shown that for the family of measurable crack free sets $\Omega$ in a bounded open holdall $D\colon \ v\in \{w\in W^{1,p}_0(D)\colon \ w= 0 \mbox{ almost everywhere on } D\backslash \Omega\}$ implies $v|_{{\rm int} {\Omega}}\in W^{1,p}_0({\rm int} {\Omega})$ . http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Applied Mathematics and Optimization Springer Journals

# Uniform Fat Segment and Cusp Properties for Compactness in Shape Optimization

, Volume 55 (3) – May 1, 2007
35 pages

/lp/springer_journal/uniform-fat-segment-and-cusp-properties-for-compactness-in-shape-oWfgN0doXR
Publisher
Springer Journals
Subject
Mathematics; Calculus of Variations and Optimal Control; Optimization; Systems Theory, Control; Mathematical and Computational Physics; Mathematical Methods in Physics; Numerical and Computational Methods
ISSN
0095-4616
eISSN
1432-0606
D.O.I.
10.1007/s00245-007-0869-6
Publisher site
See Article on Publisher Site

### Abstract

A general compactness theorem for shape/geometric analysis and optimization is given for a family of subsets verifying the uniform fat segment property in a bounded open holdall with or without constraints on the De Giorgi (11) or the γ-density perimeter of Bucur and Zolesio (3). The uniform fat segment property is shown to be equivalent to the uniform cusp property introduced in (9) with a continuous non-negative cusp function. This equivalence remains true for cusp functions that are only continuous at the origin. The equivalence of sets verifying a segment property with their C 0 -graph representation is further sharpened for sets with a compact boundary. Our C 0 -graph characterization is shown to be equivalent to both the uniform cusp property and the uniform segment property. It is used to formulate sufficient conditions on the local graphs of a family of subsets of a bounded open holdall to get compactness. A first condition assumes that the local graphs are bounded above by a cusp function; a second condition which requires that the local graphs be equicontinuous turns out to be equivalent to the first one. The respective solutions of the Laplacian with homogeneous Dirichlet or Neumann boundary condition are shown to be continuous with respect to domains in that family. In the Dirichlet case for 1 < p < ∞, we prove the (1,p)-stability of compact sets in the sense of Herdberg (14) under the weaker almost everywhere assumption rather than quasi everywhere. It is also shown that for the family of measurable crack free sets $\Omega$ in a bounded open holdall $D\colon \ v\in \{w\in W^{1,p}_0(D)\colon \ w= 0 \mbox{ almost everywhere on } D\backslash \Omega\}$ implies $v|_{{\rm int} {\Omega}}\in W^{1,p}_0({\rm int} {\Omega})$ .

### Journal

Applied Mathematics and OptimizationSpringer Journals

Published: May 1, 2007

## You’re reading a free preview. Subscribe to read the entire article.

### DeepDyve is your personal research library

It’s your single place to instantly
that matters to you.

over 18 million articles from more than
15,000 peer-reviewed journals.

All for just $49/month ### Explore the DeepDyve Library ### Search Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly ### Organize Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place. ### Access Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals. ### Your journals are on DeepDyve Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more. All the latest content is available, no embargo periods. DeepDyve ### Freelancer DeepDyve ### Pro Price FREE$49/month
\$360/year

Save searches from
PubMed

Create lists to

Export lists, citations