English

Lower and upper bounds of joint $(f,\delta)$-numerical radius functions

Functional Analysis 2026-03-20 v1

Abstract

In this study, the classical results on the joint numerical radius for nn-tuples of Hilbert space operators are extended to the setting of the joint (f,δ)(f,\delta)-numerical radius. New and diverse contributions to this area are provided, including novel estimates for the lower and upper bounds of the (f,δ)(f,\delta)-numerical radius in the context of sectorial operators.

Keywords

Cite

@article{arxiv.2603.18405,
  title  = {Lower and upper bounds of joint $(f,\delta)$-numerical radius functions},
  author = {Zameddin I. Ismailov and Sergei Silvestrov and Pembe Ipek Al},
  journal= {arXiv preprint arXiv:2603.18405},
  year   = {2026}
}