English

Rate of decay of s-numbers

Functional Analysis 2010-09-23 v1 Numerical Analysis

Abstract

For an operator TB(X,Y)T \in B(X,Y), we denote by am(T)a_m(T), cm(T)c_m(T), dm(T)d_m(T), and tm(T)t_m(T) its approximation, Gelfand, Kolmogorov, and absolute numbers. We show that, for any infinite dimensional Banach spaces XX and YY, and any sequence αm0\alpha_m \searrow 0, there exists TB(X,Y)T \in B(X,Y) for which the inequality 3αm/6am(T)max{cm(t),dm(T)}min{cm(t),dm(T)}tm(T)αm/9 3 \alpha_{\lceil m/6 \rceil} \geq a_m(T) \geq \max\{c_m(t), d_m(T)\} \geq \min\{c_m(t), d_m(T)\} \geq t_m(T) \geq \alpha_m/9 holds for every mNm \in \N. Similar results are obtained for other ss-scales.

Keywords

Cite

@article{arxiv.1009.4278,
  title  = {Rate of decay of s-numbers},
  author = {Timur Oikhberg},
  journal= {arXiv preprint arXiv:1009.4278},
  year   = {2010}
}