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About stability of equilibrium shapes

Published online by Cambridge University Press:  15 April 2002

Marc Dambrine
Affiliation:
Antenne de Bretagne de l'ENS Cachan, Institut de Recherche Mathématique de Rennes, Campus de Ker Lann, 35170 Bruz, France. (dambrine@bretagne.ens-cachan.fr)
Michel Pierre
Affiliation:
Antenne de Bretagne de l'ENS Cachan, Institut de Recherche Mathématique de Rennes, Campus de Ker Lann, 35170 Bruz, France. (pierre@bretagne.ens-cachan.fr)
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Abstract

We discuss the stability of "critical" or "equilibrium" shapes of a shape-dependent energy functional. We analyze a problem arising when looking at the positivity of the second derivative in order to prove that a critical shape is an optimal shape. Indeed, often when positivity -or coercivity- holds, it does for a weaker norm than the norm for which the functional is twice differentiable and local optimality cannot be a priori deduced. We solve this problem for a particular but significant example. We prove "weak-coercivity" of the second derivative uniformly in a "strong" neighborhood of the equilibrium shape.

Type
Research Article
Copyright
© EDP Sciences, SMAI, 2000

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