The wavelet type systems
We consider biorthogonal systems of functions on the interval [0,1] or 𝕋 which have the same dyadic scaled estimates as wavelets. We present properties and examples of these systems.
The weak distance between Banach spaces with a symmetric basis.
Three-space problems and bounded approximation properties
Let be a commuting approximating sequence of the Banach space X leaving the closed subspace A ⊂ X invariant. Then we prove three-space results of the following kind: If the operators Rₙ induce basis projections on X/A, and X or A is an -space, then both X and A have bases. We apply these results to show that the spaces and have bases whenever Λ ⊂ ℤ and ℤ∖Λ is a Sidon set.
Total Bounded Extensions of Biorthogonal Sequences in Banach Spaces.
Translation invariant projections in Sobolev spaces on tori in the L¹ and uniform norms
The idempotent multipliers on Sobolev spaces on the torus in the L¹ and uniform norms are characterized in terms of the coset ring of the dual group of the torus. This result is deduced from a more general theorem concerning certain translation invariant subspaces of vector-valued function spaces on tori.
Two geometric constants for operators acting on a separable Banach space.
The main result of this paper is the following: A separable Banach space X is reflexive if and only if the infimum of the Gelfand numbers of any bounded linear operator defined on X can be computed by means of just one sequence on nested, closed, finite codimensional subspaces with null intersection.
Two remarks on the Khintchine-Kahane inequality
Two-norm spaces and decompositions of Banach spaces, I
Type et cotype dans les espaces munis de structures locales inconditionnelles