Title of article
A gap between hyponormality and subnormality for block Toeplitz operators
Author/Authors
Hwang، نويسنده , , In Sung and Kang، نويسنده , , Dong-O and Lee، نويسنده , , Woo Young، نويسنده ,
Issue Information
دوهفته نامه با شماره پیاپی سال 2011
Pages
9
From page
883
To page
891
Abstract
This paper concerns a gap between hyponormality and subnormality for block Toeplitz operators. We show that there is no gap between 2-hyponormality and subnormality for a certain class of trigonometric block Toeplitz operators (e.g., its co-analytic outer coefficient is invertible). In addition we consider the extremal cases for the hyponormality of trigonometric block Toeplitz operators: in this case, hyponormality and normality coincide.
Keywords
Block Toeplitz operators , Matrix-valued trigonometric polynomials , Hyponormal , 2-Hyponormal , Subnormal
Journal title
Journal of Mathematical Analysis and Applications
Serial Year
2011
Journal title
Journal of Mathematical Analysis and Applications
Record number
1562081
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