Saturation of positive convolution operators

Saturation of Positive Convolution Operators RONALD

Continuityof Operators Intertwiningwith Convolution Operators

Let G be a locally compact abelian group, let m be a bounded complex-valued Borel measure on G; and let Tm be the corresponding convolution operator on LðGÞ: Let X be a Banach space and let S be a continuous linear operator on X : Then we show that every linear operator F : X ! LðGÞ such that FS 1⁄4 TmF is continuous if and only if the pair ðS;TmÞ has no critical eigenvalue. # 2002 Elsevier Sci...

Sofic groups and convolution operators

Conjecture: Let Γ be a discrete group, f ∈ L(Γ) and Tf : L (Γ) → L(Γ) be the right convolution by f . Then if Tf is injective, it is surjective as well. We prove the conjecture for the class of sofic groups. AMS Subject Classification: 43A20

Convergence of Sequences of Convolution Operators

When (φn) is a sequence of positive functions in L1(R) such that the convolutions φn ? f converge in L1-norm to f for all f ∈ L1(R), then these convolutions may or may not converge almost everywhere too. There is always a subsequence (φnk ) such that at least φnk ? f converges almost everywhere to f for all f ∈ Lp(R), 1 < p < ∞. A special case of this is when the functions φn are the dilations ...

Subordination and Super Ordination Results Involving Certain Convolution Operators