Consistency and inclusion results for Toeplitz matrices of bounded linear operators
The following result is proved: Let denote a power series space of infinite or of finite type, and equip with its canonical fundamental system of norms, R ∈ 0,∞, 1 ≤ p < ∞. Then a tamely exact sequence (⁎) exists iff α is strongly stable, i.e. , and a linear-tamely exact sequence (*) exists iff α is uniformly stable, i.e. there is A such that for all K. This result extends a theorem of Vogt and Wagner which states that a topologically exact sequence (*) exists iff α is stable, i.e. .
We survey our main results on the density condition for Fréchet spaces and on the dual density condition for (DF)-spaces (cf. Bierstedt and Bonet (1988)) as well as some recent developments.
We introduce a seminorm for bounded linear operators between Banach spaces that shows the deviation from the weak Banach-Saks property. We prove that if (Xν) is a sequence of Banach spaces and a Banach sequence lattice E has the Banach-Saks property, then the deviation from the weak Banach-Saks property of an operator of a certain class between direct sums E(Xν) is equal to the supremum of such deviations attained on the coordinates Xν. This is a quantitative version for operators of the result...
Stemming from the study of signals via wavelet coefficients, the spaces are complete metrizable and separable topological vector spaces, parametrized by a function ν, whose elements are sequences indexed by a binary tree. Several papers were devoted to their basic topology; recently it was also shown that depending on ν, may be locally convex, locally p-convex for some p > 0, or not at all, but under a minor condition these spaces are always pseudoconvex. We deal with some more sophisticated...
There is a general conjecture, the dichotomy (C) about Borel equivalence relations E: (i) E is Borel reducible to the equivalence relation where X is a Polish space, and a Polish group acting continuously on X; or (ii) a canonical relation is Borel reducible to E. (C) is only proved for special cases as in [So]. In this paper we make a contribution to the study of (C): a stronger conjecture is true for hereditary subspaces of the Polish space of real sequences, i.e., subspaces such that ...