On the Flatness of Semi-Cubically Hyponormal Weighted Shifts

• Journal title : Kyungpook mathematical journal
• Volume 48, Issue 4,  2008, pp.721-727
• Publisher : Department of Mathematics, Kyungpook National University
• DOI : 10.5666/KMJ.2008.48.4.721
Title & Authors
On the Flatness of Semi-Cubically Hyponormal Weighted Shifts
Li, Chunji; Ahn, Ji-Hye;

Abstract
Let $\small{W_{\alpha}}$ be a weighted shift with positive weight sequence $\small{{\alpha}=\{\alpha_i\}_{i=0}^{\infty}}$. The semi-cubical hyponormality of $\small{W_{\alpha}}$ is introduced and some flatness properties of $\small{W_{\alpha}}$ are discussed in this note. In particular, it is proved that if $\small{{\alpha}_n={\alpha}_{n+1}}$ for some $\small{n{\geq}1}$, $\small{{{\alpha}_{n+k}}={\alpha}_n}$ for all $\small{k{\geq}1}$.
Keywords
semi-cubically hyponormal;unilateral weighted shift;flatness;
Language
English
Cited by
1.
Flat phenomena of 2-variable weighted shifts, Linear Algebra and its Applications, 2015, 486, 234
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