Some inequalities for bounds of joint δ-numerical radius and joint δ-Crawford number functions


İSMAİLOV Z., Otkun Çevik E.

Linear and Multilinear Algebra, cilt.74, sa.2, ss.192-212, 2026 (SCI-Expanded, Scopus) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 74 Sayı: 2
  • Basım Tarihi: 2026
  • Doi Numarası: 10.1080/03081087.2026.2613296
  • Dergi Adı: Linear and Multilinear Algebra
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, MathSciNet, zbMATH
  • Sayfa Sayıları: ss.192-212
  • Anahtar Kelimeler: joint δ-Crawford number, Joint δ-numerical radius, sectorial operators
  • Karadeniz Teknik Üniversitesi Adresli: Evet

Özet

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.