English

Some $s$-numbers of an integral operator of Hardy type in Banach function spaces

Functional Analysis 2015-08-03 v1 Analysis of PDEs Classical Analysis and ODEs

Abstract

Let sn(T)s_{n}(T) denote the nnth approximation, isomorphism, Gelfand, Kolmogorov or Bernstein number of the Hardy-type integral operator TT given by Tf(x)=v(x)axu(t)f(t)dt,x(a,b)(<a<b<+) Tf(x)=v(x)\int_{a}^{x}u(t)f(t)dt,\,\,\,x\in(a,b)\,\,(-\infty<a<b<+\infty) and mapping a Banach function space EE to itself. We investigate some geometrical properties of EE for which C1abu(x)v(x)dxlim supnnsn(T)lim supnnsn(T)C2abu(x)v(x)dx C_{1}\int_{a}^{b}u(x)v(x)dx \leq\limsup\limits_{n\rightarrow\infty}ns_{n}(T) \leq \limsup\limits_{n\rightarrow\infty}ns_{n}(T)\leq C_{2}\int_{a}^{b}u(x)v(x)dx under appropriate conditions on uu and v.v. The constants C1,C2>0C_{1},C_{2}>0 depend only on the space E.E.

Keywords

Cite

@article{arxiv.1507.08854,
  title  = {Some $s$-numbers of an integral operator of Hardy type in Banach function spaces},
  author = {David Edmunds and Amiran Gogatishvili and Tengiz Kopaliani and Nino Samashvili},
  journal= {arXiv preprint arXiv:1507.08854},
  year   = {2015}
}