• 제목/요약/키워드: semi-cubic hyponormality

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SEMI-CUBICALLY HYPONORMAL WEIGHTED SHIFTS WITH STAMPFLI'S SUBNORMAL COMPLETION

  • Baek, Seunghwan;Lee, Mi Ryeong
    • 대한수학회논문집
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    • 제34권2호
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    • pp.477-486
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    • 2019
  • Let ${\alpha}:1,(1,{\sqrt{x}},{\sqrt{y}})^{\wedge}$ be a weight sequence with Stampfli's subnormal completion and let $W_{\alpha}$ be its associated weighted shift. In this paper we discuss some properties of the region ${\mathcal{U}}:=\{(x,y):W_{\alpha}$ is semi-cubically hyponormal} and describe the shape of the boundary of ${\mathcal{U}}$. In particular, we improve the results of [19, Theorem 4.2].