Extensions of weak type multipliers

m at h . FA ] 1 0 Ja n 20 02 EXTENSIONS OF WEAK - TYPE MULTIPLIERS

In this paper we prove that if Λ ∈ M p (R N) and has compact support then Λ is a weak summability kernel for 1 < p <

Weak Compactness of the Set of ε-Extensions

Weak Type Estimates for Spherical Multipliers on Noncompact Symmetric Spaces

In this paper we prove sharp weak type 1 estimates for spherical Fourier multipliers on symmetric spaces of the noncompact type. This complements earlier results of J.-Ph. Anker and A.D. Ionescu.

weak compactness of the set of ε-extensions

The Structure of Weak Coalgebra-galois Extensions

Weak coalgebra-Galois extensions are studied. A notion of an invertible weak entwining structure is introduced. It is proven that, within an invertible weak entwining structure, the surjectivity of the canonical map implies bijectivity provided the structure coalgebra C is either coseparable or projective as a C-comodule.