Two-dimensional Helmholtz spaces.
Two-jets of conformal fields along their zero sets
The connected components of the zero set of any conformal vector field v, in a pseudo-Riemannian manifold (M, g) of arbitrary signature, are of two types, which may be called ‘essential’ and ‘nonessential’. The former consist of points at which v is essential, that is, cannot be turned into a Killing field by a local conformal change of the metric. In a component of the latter type, points at which v is nonessential form a relatively-open dense subset that is at the same time a totally umbilical...
Two-spinor tetrad and Lie derivatives of Einstein-Cartan-Dirac fields
An integrated approach to Lie derivatives of spinors, spinor connections and the gravitational field is presented, in the context of a previously proposed, partly original formulation of a theory of Einstein-Cartan-Maxwell-Dirac fields based on “minimal geometric data”: the needed underlying structure is determined, via geometric constructions, from the unique assumption of a complex vector bundle with 2-dimensional fibers, called a -spinor bundle. Any further considered object is assumed to...
Über aus einem k-Bein bildbare Übertragungsparameter
Über die Finslerschen Räume mit konform verallgemeinerter Struktur.
Über die isometrische Fortsetzbarkeit isometrischer Immersionen der Standard-m-Sphäre Sm(< Rm+1) in Rm+2.
Über die Konstruktion von metrisch-affinen Räumen von rekurrenter Krümmung
Über die Krümmung in der Variationsrechnung. (Mit 6 Figuren im Text)
Über die Riemannsche Einbettungsgeometrie der Veronesemannigfaltigkeiten.
Über die Totalkrümmung.
Une approche pédestre de quelques aspects locaux des variétés de Cauchy-Riemann
Une connexion non-symétrique associée à l'espace riemannien.
Une nouvelle classe de solutions des équations d'Einstein à symétrie sphérique. Application à des modèles cosmologiques multi-couches
Une perturbation à symétrie sphérique de la métrique d'un univers en expansion
Uniform Finsler Hadamard manifolds
Uniqueness and non-existence of metrics with prescribed Ricci curvature
Universal isomonodromic deformations of meromorphic rank 2 connections on curves
We consider tracefree meromorphic rank 2 connections over compact Riemann surfaces of arbitrary genus. By deforming the curve, the position of the poles and the connection, we construct the global universal isomonodromic deformation of such a connection. Our construction, which is specific to the tracefree rank 2 case, does not need any Stokes analysis for irregular singularities. It is thereby more elementary than the construction in arbitrary rank due to B. Malgrange and I. Krichever and it includes...
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Untermannigfaltigkeiten reduktiver Räume