arXiv subjects
Herve Queffelec
Publications and source records attributed to Herve Queffelec.
A criterion of weak compactness for operators on subspaces of Orlicz spaces
To appear in J. Funct. Spaces and Appl.
Compact composition operators on $H^2$ and Hardy-Orlicz spaces
We compare the compactness of composition operators on $H^2$ and on Orlicz-Hardy spaces $H^Ψ$. We show in particular that exists an Orlicz function $Ψ$ such that $H^{3+\eps} \subseteq H^Ψ\subseteq H^3$ for every $\eps >0$, and a composition operator $C_ϕ$ which is compact on $H^3$ and on $H^{3+\eps}$, but not compact on $H^Ψ$.
Some Remarks on the Algebra of Bounded Dirichlet Series
We examine the algebra of all Dirichlet Series bounded on the right half plane. We consider the analogue of the Corona theorem in this setting, and show that it is false, i.e. the right half-plane is not dense in the maximal ideal space. We also prove some refinements of the Hille-Bohnenblust theorem, where both probabilistic and deterministic devices are used, and we show how the proof is carried out for each.