On almost complex structures from classical linear connections
Journal Title: Annales Universitatis Mariae Curie-Skłodowska. Sectio A, Mathematica - Year 2017, Vol 71, Issue 1
Abstract
Let Mfm be the category of m-dimensional manifolds and local diffeomorphisms and let T be the tangent functor on Mfm. Let V be the category of real vector spaces and linear maps and let Vm be the category of m-dimensional real vector spaces and linear isomorphisms. We characterize all regular covariant functors F:Vm→V admitting Mfm-natural operators J transforming classical linear connections ∇ on m-dimensional manifolds M into almost complex structures J(∇) on F(T)M=⋃x∈MF(TxM).
Authors and Affiliations
Jan Kurek, Włodzimierz Mikulski
Keywords
Related Articles
- EP ID EP304684
- DOI 10.17951/a.2017.71.1.55
- Views 137
- Downloads 0
The density Turan problem for 3-uniform linear hypertrees. An efficient testing algorithm
Let T = (V, E) be a 3-uniform linear hypertree. We consider a blow-up hypergraph B[T ]. We are interested in the following problem. We have to decide whether there exists a blow-up hypergraph B[T ] of the hypertree T , w...
On the existence of connections with a prescribed skew-symmetric Ricci tensor
We study the so-called inverse problem. Namely, given a prescribed skew-symmetric Ricci tensor we find (locally) a respective linear connection.
The Riemann-Cantor uniqueness theorem for unilateral trigonometric series via a special version of the Lusin-Privalov theorem
Using Baire's theorem, we give a very simple proof of a special version of the Lusin-Privalov theorem and deduce via Abel's theorem the Riemann-Cantor theorem on the uniqueness of the coefficients of pointwise converge...
Invo-regular unital rings
It was asked by Nicholson (Comm. Algebra, 1999) whether or not unit-regular rings are themselves strongly clean. Although they are clean as proved by Camillo–Khurana (Comm. Algebra, 2001), recently Nielsen and ˇSter show...
On branchwise commutative pseudo-BCH algebras
Basic properties of branches of pseudo-BCH algebras are described. Next, the concept of a branchwise commutative pseudo-BCH algebra is introduced. Some conditions equivalent to branchwise commutativity are given. It is p...