On the inequality of Mathieu.
On the Limits of Simple Means.
On the metric dimension of converging sequences
In the paper, some kind of independence between upper metric dimension and natural order of converging sequences is shown — for any sequence converging to zero there is a greater sequence with an arbitrary () upper dimension. On the other hand there is a relationship to summability of series — the set of elements of any positive summable series must have metric dimension less than or equal to .
On the strong lacunary convergence and strong Cesàro summability of sequences of real-valued functions.
On Three Problems For Sequences.
On totally non-commutative convergence groupoids
On transfinite sequences of B-measurable functions
On weak statistical convergence.
On -valued sequence spaces.
On -convergence of sequences
On -statistically convergent double sequences of fuzzy numbers.
On -convergence and -density
p-Analytic and p-quasi-analytic vectors
For every symmetric operator acting in a Hilbert space, we introduce the families of p-analytic and p-quasi-analytic vectors (p>0), indexed by positive numbers. We prove various properties of these families. We make use of these families to show that certain results guaranteeing essential selfadjointness of an operator with sufficiently large sets of quasi-analytic and Stieltjes vectors are optimal.
Permutations preserving sums of rearranged real series
The aim of this paper is to discuss one of the most interesting and unsolved problems of the real series theory: rearrangements that preserve sums of series. Certain hypothesis about combinatorial description of the corresponding permutations is presented and basic algebraic properties of the family , introduced by it, are investigated.
Polynomial two-point expansions.
Power series in locally convex algebras
Power-monotone sequences and Fourier series with positive coefficients.
Power-monotone sequences and Fourier series with positive coefficients.
Poznámky k nekonečným řadám
Propriété de deux suites sommables