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Size minimizing surfaces

Thierry De Pauw (2009)

Annales scientifiques de l'École Normale Supérieure

We prove a new existence theorem pertaining to the Plateau problem in 3 -dimensional Euclidean space. We compare the approach of E.R. Reifenberg with that of H. Federer and W.H. Fleming. A relevant technical step consists in showing that compact rectifiable surfaces are approximatable in Hausdorff measure and in Hausdorff distance by locally acyclic surfaces having the same boundary.

Ski de fond

Alain Dufresnoy (1983/1984)

Séminaire de théorie spectrale et géométrie

Smoothness and geometry of boundaries associated to skeletal structures I: sufficient conditions for smoothness

James Damon (2003)

Annales de l’institut Fourier

We introduce a skeletal structure ( M , U ) in n + 1 , which is an n - dimensional Whitney stratified set M on which is defined a multivalued “radial vector field” U . This is an extension of notion of the Blum medial axis of a region in n + 1 with generic smooth boundary. For such a skeletal structure there is defined an “associated boundary” . We introduce geometric invariants of the radial vector field U on M and a “radial flow” from M to . Together these allow us to provide sufficient numerical conditions for...

Soldered double linear morphisms

Alena Vanžurová (1992)

Mathematica Bohemica

Our aim is to show a method of finding all natural transformations of a functor T T * into itself. We use here the terminology introduced in [4,5]. The notion of a soldered double linear morphism of soldered double vector spaces (fibrations) is defined. Differentiable maps f : C 0 C 0 commuting with T T * -soldered automorphisms of a double vector space C 0 = V * × V × V * are investigated. On the set Z s ( C 0 ) of such mappings, appropriate partial operations are introduced. The natural transformations T T * T T * are bijectively related with the elements...

Some aspects of the homogeneous formalism in field theory and gauge invariance

Marcella Palese, Ekkehart Winterroth (2006)

Archivum Mathematicum

We propose a suitable formulation of the Hamiltonian formalism for Field Theory in terms of Hamiltonian connections and multisymplectic forms where a composite fibered bundle, involving a line bundle, plays the role of an extended configuration bundle. This new approach can be interpreted as a suitable generalization to Field Theory of the homogeneous formalism for Hamiltonian Mechanics. As an example of application, we obtain the expression of a formal energy for a parametrized version of the Hilbert–Einstein...

Some functorial prolongations of general connections

Ivan Kolář (2018)

Archivum Mathematicum

We consider the problem of prolongating general connections on arbitrary fibered manifolds with respect to a product preserving bundle functor. Our main tools are the theory of Weil algebras and the Frölicher-Nijenhuis bracket.

Some geometric aspects of the calculus of variations in several independent variables

David Saunders (2010)

Communications in Mathematics

This paper describes some recent research on parametric problems in the calculus of variations. It explains the relationship between these problems and the type of problem more usual in physics, where there is a given space of independent variables, and it gives an interpretation of the first variation formula in this context in terms of cohomology.

Some liftings of Poisson structures to Weil bundles

Jacek Dębecki (2006)

Czechoslovak Mathematical Journal

We establish a formula for the Schouten-Nijenhuis bracket of linear liftings of skew-symmetric tensor fields to any Weil bundle. As a result we obtain a construction of some liftings of Poisson structures to Weil bundles.

Some natural operators on vector fields

Jiří M. Tomáš (1995)

Archivum Mathematicum

We determine all natural operators transforming vector fields on a manifold M to vector fields on T * T 1 2 M , dim M 2 , and all natural operators transforming vector fields on M to functions on T * T T 1 2 M , dim M 3 . We describe some relations between these two kinds of natural operators.

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