Journal article
Subnormal block Toeplitz operators
Journal d'analyse mathématique (Jerusalem), Vol.155(2), pp.485-500
04/2025
DOI: 10.1007/s11854-025-0358-3
Abstract
In this paper we consider the subnormality of block Toeplitz operators T, where is an n × n matrix-valued function on the unit circle T of the form = Q∗ (Q is a finite Blaschke–Potapov product).
This is related to a matrix-valued version of Halmos’ Problem 5 and the Nakazi–Takahashi Theorem. We ask whether T is either normal or analytic if T is subnormal, where is of the above form. We give answers to this problem for different cases of the symbol. Moreover, we provide a sufficient condition for the answer to be affirmative when ∗ is not of bounded type
Details
- Title: Subtitle
- Subnormal block Toeplitz operators
- Creators
- Mankunikuzhiyil Abhinand - University of CalicutRaúl E. Curto - University of IowaIn Sung Hwang - Sungkyunkwan UniversityWoo Young Lee - Korea Institute for Advanced StudyThankarajan Prasad - University of Calicut
- Resource Type
- Journal article
- Publication Details
- Journal d'analyse mathématique (Jerusalem), Vol.155(2), pp.485-500
- DOI
- 10.1007/s11854-025-0358-3
- ISSN
- 0021-7670
- eISSN
- 1565-8538
- Publisher
- HEBREW UNIV MAGNES PRESS; JERUSALEM
- Grant note
- Junior Research Fellowship, University Grant commission, Government of IndiaNRF(Korea): 2021R1A2C1005428 Mathematical Research Impact Centric Support, MATRICS: MTR/2021/000373 SERB, Department of Science and Technology (DST), Government of India
The authors are grateful to the Referee for a detailed reading of the paper and for helpful suggestions. The first-named author (Abhinand M.) was supported by the Junior Research Fellowship, University Grant commission, Government of India. The third-named author (I. S. Hwang) was supported by NRF(Korea) grant No. 2022R1A2C1010830. The fourth-named author (W. Y. Lee) was supported by NRF(Korea) grant No. 2021R1A2C1005428. The fifth-named author (Prasad T.) was supported in part by the Mathematical Research Impact Centric Support, MATRICS (MTR/2021/000373) by SERB, Department of Science and Technology (DST), Government of India.
- Language
- English
- Electronic publication date
- 01/21/2025
- Date published
- 04/2025
- Academic Unit
- Mathematics
- Record Identifier
- 9984781273002771
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