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;

Li, Chunji; Ahn, Ji-Hye;

Abstract

Let be a weighted shift with positive weight sequence . The semi-cubical hyponormality of is introduced and some flatness properties of are discussed in this note. In particular, it is proved that if for some , for all .

Keywords

semi-cubically hyponormal;unilateral weighted shift;flatness;

Language

English

Cited by

References

1.

Y. Choi, A propagation of quadratically hyponormal weighted shifts, Bull. Korean Math. Soc., 37(2000), 347-352.

2.

R. Curto, Quadratically hyponormal weighted shifts, Integral Equations and Operator Theory, 13(1990), 49-66.

3.

R. Curto, Joint hyponormality: A bridge between hyponormality and subnormality, Proc. Symposia Pure Math., 51(1990), Part II, 69-91.

4.

R. Curto and L. Fialkow, Recursively generated weighted shifts and the subnormal completion problem, I, Integral Equations and Operator Theory, 17(1993), 202-246.

5.

R. Curto and L. Fialkow, Recursively generated weighted shifts and the subnormal completion problem, II, Integral Equations and Operator Theory, 18(1994), 369-426.

6.

R. Curto and I. Jung, Quadratically hyponormal weighted shifts with two equal weights, Integral Equations and Operator Theory, 37(2000), 208-231.

7.

R. Curto and M. Putinar, Nearly subnormal operators and moment problems, J. Funct. Anal., 115(1993), 480-497.

8.

I. Jung and S. Park, Quadratically hyponormal weighted shifts and their examples, Integral Equations and Operator Theory, 36(2000), 480-498.

9.

I. Jung and S. Park, Cubically hyponormal weighted shifts and their examples, J. Math. Anal. Appl., 247(2000), 557-569.

11.

R. Sweet, A recursive relation for the determinant of a pentadiagonal matrix, Comm ACM, 12(1969), 330-332.

12.

Wolfram Research, Inc. Mathematica, Version 3.0, Wolfram Research Inc., Champaign, IL, 1996.