Displaying 6381 – 6400 of 13227

Showing per page

On a question of C c ( X )

A. R. Olfati (2016)

Commentationes Mathematicae Universitatis Carolinae

In this short article we answer the question posed in Ghadermazi M., Karamzadeh O.A.S., Namdari M., On the functionally countable subalgebra of C ( X ) , Rend. Sem. Mat. Univ. Padova 129 (2013), 47–69. It is shown that C c ( X ) is isomorphic to some ring of continuous functions if and only if υ 0 X is functionally countable. For a strongly zero-dimensional space X , this is equivalent to say that X is functionally countable. Hence for every P -space it is equivalent to pseudo- 0 -compactness.

On a question of Mbekhta.

Christoph Schmoeger (2005)

Extracta Mathematicae

The present paper deals with a question of M. Mbekhta concerning partial isometries on Banach spaces.

On a Question of Pełczyński about Strictly Singular Operators

Jesús M. F. Castillo, Marilda Simoes, Jesús Suárez de la Fuente (2012)

Bulletin of the Polish Academy of Sciences. Mathematics

We exhibit new examples of weakly compact strictly singular operators with dual not strictly cosingular and characterize the weakly compact strictly singular surjections with strictly cosingular adjoint as those having strictly singular bitranspose. We then obtain new examples of super-strictly singular quotient maps and show that the strictly singular quotient maps in Kalton-Peck sequences are not super-strictly singular.

On a relation between norms of the maximal function and the square function of a martingale

Masato Kikuchi (2013)

Colloquium Mathematicae

Let Ω be a nonatomic probability space, let X be a Banach function space over Ω, and let ℳ be the collection of all martingales on Ω. For f = ( f ) n , let Mf and Sf denote the maximal function and the square function of f, respectively. We give some necessary and sufficient conditions for X to have the property that if f, g ∈ ℳ and | | M g | | X | | M f | | X , then | | S g | | X C | | S f | | X , where C is a constant independent of f and g.

Currently displaying 6381 – 6400 of 13227