Some New Applications of Berezin Symbols

---

istinad üçün kopyala

Bhunia P., Garayev M. T., Paul K., Tapdigoglu R.

COMPLEX ANALYSIS AND OPERATOR THEORY, vol.17, no.6, 2023 (SCI-Expanded)

• Nəşrin Növü: Article / Article
• Cild: 17 Say: 6
• Nəşr tarixi: 2023
• Doi nömrəsi: 10.1007/s11785-023-01404-1
• jurnalın adı: COMPLEX ANALYSIS AND OPERATOR THEORY
• Jurnalın baxıldığı indekslər: Science Citation Index Expanded (SCI-EXPANDED), Scopus, MathSciNet, zbMATH
• Adres: Bəli

Qısa məlumat

We study some problems of operator theory by using Berezin symbols approach. Namely, we investigate in terms of Berezin symbols invariant subspaces of isometric composition operators on H (Omega). We discuss operator corona problem, in particular, the Toeplitz corona problem. Further, we characterize unitary operators in terms of Berezin symbols. We show that the well known inequality w (A) >= 1/2 parallel to A parallel to for numerical radius is not true for the Berezin number of operators, which is defined) by ber (A) := sup(lambda is an element of Omega) vertical bar(a) over tilde(lambda)vertical bar where (A) over tilde (lambda) := < A (k) over tilde (lambda,) k(lambda)> is the Berezin symbol of operator A : H (Omega) -> H (Omega). Finally, we provide a lower bound for ber (A) .