Now showing items 1-10 of 27
Generalized (κ,μ)-space forms [Article]
Generalized (κ, µ)-space forms are introduced and studied. We examine in depth the contact metric case and present examples for all possible dimensions. We also analyse the trans-Sasakian case.
The contact number of a pseudo-Euclidean submanifold [Article]
(Mathematical Society of the Republic of China, 2008-10)
In this paper we define the contact number of a pseudo-Riemannian submanifold into the pseudo-Euclidean space, and prove that this contact number is closely related to the notion of pseudo-isotropic submanifold. We give ...
On the Freudenthal extensions of proper confluent maps [Article]
(University of Houston, 2012)
In this paper we study when Freudenthal extensions of proper maps preserve the (weak, semi) confluency. Also the extensions to the Alexandroff one-point compactificaton are considered.
Some relationships between intrinsic and extrinsic invariants of submanifolds in generalized S-space-forms [Article]
(Hacettepe University, 2015)
We establish some inequalities of Chen’s type between certain intrinsic invariants (involving sectional, Ricci and scalar curvatures) and the squared mean curvature of submanifolds tangent to the structure vector fields ...
Irreducible triangulations of the once-punctured torus [Article]
(Sobolev Institute of Mathematics, 2018)
A triangulation of a surface with fixed topological type is called irreducible if no edge can be contracted to a vertex while remaining in the category of simplicial complexes and preserving the topology of the surface. A ...
A historical perspective of the theory of isotopisms [Article]
In the middle of the twentieth century, Albert and Bruck introduced the theory of isotopisms of non-associative algebras and quasigroups as a generalization of the classical theory of isomorphisms in order to study and ...
New relationships involving the mean curvature of slant submanifolds in S-space-forms [Article]
(Korean Mathematical Society, 2007)
Relationships between the Ricci curvature and the squared mean curvature and between the shape operator associated with the mean curvature vector and the sectional curvature function for slant submanifolds of an S-space-form ...
Isotropic submanifolds of pseudo-Riemannian spaces [Article]
The family of all the submanifolds of a given Riemannian or pseudo-Riemannian manifold is large enough to classify them into some interesting subfamilies such as minimal (maximal), totally geodesic, Einstein, etc. Most of ...
The contact magnetic flow in 3D Sasakian manifolds [Article]
(IOP Publishing, 2009-05-15)
We first present a geometrical approach to magnetic fields in three-dimensional Riemannian manifolds, because this particular dimension allows one to easily tie vector fields and 2-forms. When the vector field is divergence ...
Isotropy and marginally trapped surfaces in a spacetime [Article]
(IOP Publishing, 2010)
In this note we shall study the notions of isotropic and marginally trapped surface in a spacetime by using a differential geometric approach. We first consider spacelike isotropic surfaces in a Lorentzian manifold and, ...