Descriptive collineations in spaces of $K$-spreads

Collineations in Generalized Spaces

Maximal Partial Spreads of Polar Spaces

Some constructions of maximal partial spreads of finite classical polar spaces are provided. In particular we show that, for n > 1, H(4n−1, q2) has a maximal partial spread of size q2n + 1, H(4n + 1, q2) has a maximal partial spread of size q2n+1 + 1 and, for n > 2, Q+(4n − 1, q), Q(4n − 2, q), W(4n − 1, q), q even, W(4n − 3, q), q even, have a maximal partial spread of size qn + 1.

Continuous $k$-Fusion Frames in Hilbert Spaces

The study of the c$k$-fusions frames shows that the emphasis on the measure spaces introduces a new idea, although some similar properties with the discrete case are raised. Moreover, due to the nature of measure spaces, we have to use new techniques for new results. Especially, the topic of the dual of frames  which is important for frame applications, have been specified  completely for the c...

Weyl collineations that are not curvature collineations

Though the Weyl tensor is a linear combination of the curvature tensor, Ricci tensor and Ricci scalar, it does not have all and only the Lie symmetries of these tensors since it is possible, in principle, that “asymmetries cancel”. Here we investigate if, when and how the symmetries can be different. It is found that we can obtain a metric with a finite dimensional Lie algebra of Weyl symmetrie...

Some Properties of Continuous $K$-frames in Hilbert Spaces

The theory of  continuous frames in Hilbert spaces is extended, by using the concepts of measure spaces, in order to get the results of a new application of operator theory.  The $K$-frames were  introduced by G$breve{mbox{a}}$vruta (2012) for Hilbert spaces to study atomic systems with respect to a bounded linear operator. Due to the structure of  $K$-frames, there are many differences between...