English

On the essential norms of Toeplitz operators with continuous symbols

Functional Analysis 2020-07-28 v1 Spectral Theory

Abstract

It is well known that the essential norm of a Toeplitz operator on the Hardy space Hp(T)H^p(\mathbb{T}), 1<p<1 < p < \infty is greater than or equal to the L(T)L^\infty(\mathbb{T}) norm of its symbol. In 1988, A. B\"ottcher, N. Krupnik, and B. Silbermann posed a question on whether or not the equality holds in the case of continuous symbols. We answer this question in the negative. On the other hand, we show that the essential norm of a Toeplitz operator with a continuous symbol is less than or equal to twice the L(T)L^\infty(\mathbb{T}) norm of the symbol and prove more precise pp-dependent estimates.

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Cite

@article{arxiv.2007.13178,
  title  = {On the essential norms of Toeplitz operators with continuous symbols},
  author = {Eugene Shargorodsky},
  journal= {arXiv preprint arXiv:2007.13178},
  year   = {2020}
}