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Calculus of variations with differential forms

Saugata Bandyopadhyay, Bernard Dacorogna, Swarnendu Sil (2015)

Journal of the European Mathematical Society

We study integrals of the form Ω f d ω , where 1 k n , f : Λ k is continuous and ω is a k - 1 -form. We introduce the appropriate notions of convexity, namely ext. one convexity, ext. quasiconvexity and ext. polyconvexity. We study their relations, give several examples and counterexamples. We finally conclude with an application to a minimization problem.

Champs de vecteurs et formes différentielles sur une variété des points proches

Basile Guy Richard Bossoto, Eugène Okassa (2008)

Archivum Mathematicum

Let M be a smooth manifold, A a local algebra in sense of André Weil, M A the manifold of near points on M of kind A and 𝔛 ( M A ) the module of vector fields on M A . We give a new definition of vector fields on M A and we show that 𝔛 ( M A ) is a Lie algebra over A . We study the cohomology of A -differential forms. Résumé. On considère M une variété différentielle, A une algèbre locale au sens d’André Weil, M A la variété des points proches de M d’espèce A et 𝔛 ( M A ) le module des champs de vecteurs sur M A . On donne une nouvelle...

Decomposition in the large of two-forms of constant rank

Ibrahim Dibag (1974)

Annales de l'institut Fourier

The purpose of this paper is to find necessary and sufficient conditions for globally-decomposing an exterior 2-form w , of constant rank 2 s , on a vector-bundle E , as a sum : w = y 1 y s + 1 + + y s y 2 s . The general theory is applied to low dimensional manifolds, spheres, real and complex projective spaces.

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