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Flow prolongation of some tangent valued forms

Antonella Cabras, Ivan Kolář (2008)

Czechoslovak Mathematical Journal

We study the prolongation of semibasic projectable tangent valued k -forms on fibered manifolds with respect to a bundle functor F on local isomorphisms that is based on the flow prolongation of vector fields and uses an auxiliary linear r -th order connection on the base manifold, where r is the base order of F . We find a general condition under which the Frölicher-Nijenhuis bracket is preserved. Special attention is paid to the curvature of connections. The first order jet functor and the tangent...

Foliations by surfaces of a peculiar class

Adam Bartoszek, Paweł Walczak (2008)

Annales Polonici Mathematici

We classify surfaces in 3-dimensional space forms which have all the local conformal invariants constant and show that compact 3-manifolds of nonzero constant sectional curvature admit no foliations by such surfaces.

Foliations of lightlike hypersurfaces and their physical interpretation

Krishan Duggal (2012)

Open Mathematics

This paper deals with a family of lightlike (null) hypersurfaces (H u) of a Lorentzian manifold M such that each null normal vector ℓ of H u is not entirely in H u, but, is defined in some open subset of M around H u. Although the family (H u) is not unique, we show, subject to some reasonable condition(s), that the involved induced objects are independent of the choice of (H u) once evaluated at u = constant. We use (n+1)-splitting Lorentzian manifold to obtain a normalization of ℓ and a well-defined...

Fonctionnelles invariantes et courants basiques

A. Abouqateb, A. El Kacimi Alaoui (2000)

Studia Mathematica

Dans ce travail: (1) on caractérise l’espace C G des fonctionnelles invariantes par un groupe compact G opérant linéairement et continûment sur un espace vectoriel topologique localement convexe séparé et séquentiellement complet E plus précisément, on montre que C G est le dual topologique du sous-espace E G des vecteurs de E qui sont G-invariants. (2) On étudie les courants basiques sur une variété feuilletée (V,ℱ). On obtient alors, dans le cas où le feuilletage est associé à une action localement...

Currently displaying 1561 – 1580 of 5556