Central Lacunary Sets.
Characterization of Fourier Transforms of Vector Valued Functions and Measures
Characterization of measures in the group C*-algebra of a locally compact group.
Characterization, Structure and Analysis on Abelian ... Groups.
Characterizing Sidon sets by interpolation properties of subsets
Pisier's characterization of Sidon sets as containing proportional-sized quasi-independent subsets is given a sharper form for groups with only a finite number of elements having orders a power of 2. No such improvement is possible for a general Sidon subset of a group having an infinite number of elements of order 2. The method used also gives several sharper forms of Ramsey's characterization of Sidon sets as containing proportional-sized I₀-subsets in a uniform way, again in groups containing...
Comparison theorem between Fourier transform and Fourier transform with compact support
We prove a comparison theorem between Fourier transform without support and and Fourier transform with compact support in the context of arithmetic -modules.
Complemented ideals of group algebras
The existence of a projection onto an ideal I of a commutative group algebra depends on its hull Z(I) ⊆ Ĝ. Existing methods for constructing a projection onto I rely on a decomposition of Z(I) into simpler hulls, which are then reassembled one at a time, resulting in a chain of projections which can be composed to give a projection onto I. These methods are refined and examples are constructed to show that this approach does not work in general. Some answers are also given to previously asked...
Complex powers and asymptotic expansions. I. Functions of certain types.
Complex powers and asymptotic expansions. II.
Complex Unconditional Metric Approximation Property for spaces
We study the Complex Unconditional Metric Approximation Property for translation invariant spaces of continuous functions on the circle group. We show that although some “tiny” (Sidon) sets do not have this property, there are “big” sets Λ for which has (ℂ-UMAP); though these sets are such that contains functions which are not continuous, we show that there is a linear invariant lifting from these spaces into the Baire class 1 functions.
Constructions of singular measures with remarkable convolution properties
Continuous measures and analytic sets
Convolution Quotients of Nonnegative Functions.
Correction to the paper "Some problems and remarks on relative multipliers''