Journal of applied mathematics & informatics

한국전산응용수학회 (The Korean Society for Computational and Applied Mathematics)
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WHICH WEIGHTED SHIFTS ARE FLAT ?

  • SHEN, HAILONG (Department of Mathematics, Northeastern University) ;
  • LI, CHUNJI (Department of Mathematics, Northeastern University)
  • 투고 : 2020.04.08
  • 심사 : 2020.05.13
  • 발행 : 2020.09.30
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초록

The flatness property of a unilateral weighted shifts is important to study the gaps between subnormality and hyponormality. In this paper, we first summerize the results on the flatness for some special kinds of a weighted shifts. And then, we consider the flatness property for a local-cubically hyponormal weighted shifts, which was introduced in [2]. Let α : ${\sqrt{\frac{2}{3}}}$, ${\sqrt{\frac{2}{3}}}$, $\{{\sqrt{\frac{n+1}{n+2}}}\}^{\infty}_{n=2}$ and let Wα be the associated weighted shift. We prove that Wα is a local-cubically hyponormal weighted shift Wα of order ${\theta}={\frac{\pi}{4}}$ by numerical calculation.

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참고문헌

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