Some inequalities for bounds of joint δ -numerical radius and joint δ -Crawford number functions
Abstract
The primary objective of this study is to derive evaluation formulas for the lower and upper bounds of the joint δ-numerical radius and the joint δ-Crawford number functions. Subsequently, several significant estimates for these bounds are presented in the context of sectorial coordinate operators. The results obtained not only extend certain well-known findings in the recent literature but also contribute novel and practical insights to the field. Another aim of this work is to enrich the existing theory by offering alternative and useful results in this area.
Fields of Study & Subjects
Mathematical Inequalities and Applications
Mathematical functions and polynomials
Analytic and geometric function theory
Publication details
- Journal / source
- Linear and Multilinear Algebra
- Publisher
- Informa UK Limited
- Volume
- 74
- Issue
- 2
- Pages
- 192–212
- Publication date
- 7 January 2026
- Language
- EN