Sabinin‘s method for classification of local Bol loops
Given a fibered manifold , a 2-connection on means a section . The authors determine all first order natural operators transforming a 2-connection on and a classical linear connection on into a connection on . (The proof implies that there is no first order natural operator transforming 2-connections on into connections on .) Using this result, the authors deduce several properties of characterizable connections on .
Motivated by the study of CR-submanifolds of codimension in , the authors consider here a -dimensional oriented manifold equipped with a -dimensional distribution. Under some non-degeneracy condition, two different geometric situations can occur. In the elliptic case, one constructs a canonical almost complex structure on ; the hyperbolic case leads to a canonical almost product structure. In both cases the only local invariants are given by the obstructions to integrability for these structures....
The author presents a simple method (by using the standard theory of connections on principle bundles) of -decomposition of the physical equations written in terms of differential forms on a 4-dimensional spacetime of general relativity, with respect to a general observer. Finally, the author suggests possible applications of such a decomposition to the Maxwell theory.
For a three-web of codimension on a differentiable manifold of dimension , the author studies the Chern connection and a family of parallelizing connections. The latter ones have a common property with the former: the web-distributions are parallel with respect to them.
This is a survey of recent contributions to the area of special Kähler geometry. A (pseudo-)Kähler manifold is a differentiable manifold endowed with a complex structure and a (pseudo-)Riemannian metric such that i) is orthogonal with respect to the metric ii) is parallel with respect to the Levi Civita connection A special Kähler manifold is a Kähler manifold together with a flat torsionfree connection such that i) where is the Kähler form and ii) is symmetric. A holomorphic...
The paper represents the lectures given by the author at the 16th Winter School on Geometry and Physics, Srni, Czech Republic, January 13-20, 1996. He develops in an elegant manner the theory of conformal covariants and the theory of functional determinant which is canonically associated to an elliptic operator on a compact pseudo-Riemannian manifold. The presentation is excellently realized with a lot of details, examples and open problems.
This paper deals with Dirac, twistor and Killing equations on Weyl manifolds with -spin structures. A conformal Schrödinger-Lichnerowicz formula is presented and used to derive integrability conditions for these equations. It is shown that the only non-closed Weyl manifolds of dimension greater than 3 that admit solutions of the real Killing equation are 4-dimensional and non-compact. Any Weyl manifold of dimension greater than 3, that admits a real Killing spinor has to be Einstein-Weyl.