JOURNAL BROWSE
Search
Advanced SearchSearch Tips
An Algorithm for Quartically Hyponormal Weighted Shifts
facebook(new window)  Pirnt(new window) E-mail(new window) Excel Download
  • Journal title : Kyungpook mathematical journal
  • Volume 51, Issue 2,  2011, pp.187-194
  • Publisher : Department of Mathematics, Kyungpook National University
  • DOI : 10.5666/KMJ.2011.51.2.187
 Title & Authors
An Algorithm for Quartically Hyponormal Weighted Shifts
Baek, Seung-Hwan; Jung, Il-Bong; Moo, Gyung-Young;
  PDF(new window)
 Abstract
Examples of a quartically hyponormal weighted shift which is not 3-hyponormal are discussed in this note. In [7] Exner-Jung-Park proved that if (x) : with 0 < x , then is quartically hyponormal but not 4-hyponormal. And, Curto-Lee([5]) improved their result such as that if : with 0 < x , then is quartically hyponormal but not 3-hyponormal. In this note, we improve slightly Curto-Lee's extremal value by using an algorithm and computer software tool.
 Keywords
quartically hyponormal operators;cubically hyponormal operators;quadratically hyponormal operators;weighted shifts;
 Language
English
 Cited by
1.
Backward Extensions of Recursively Generated Weighted Shifts and Quadratic Hyponormality, Integral Equations and Operator Theory, 2014, 79, 1, 49  crossref(new windwow)
2.
Quadratically hyponormal weighted shifts with recursive tail, Journal of Mathematical Analysis and Applications, 2013, 408, 1, 298  crossref(new windwow)
 References
1.
R. Curto, Quadratically hyponormal weighted shifts, Integral Equations Operator Theory, 13(1990), 49-66. crossref(new window)

2.
R. Curto and L. Fialkow, Recursively generated weighted shifts and the subnormal completion problem, Integral Equations Operator Theory, 17(1993), 202-246. crossref(new window)

3.
R. Curto and L. Fialkow, Recursively generated weighted shifts and the subnormal completion problem, II, Integral Equations Operator Theory, 17(1993), 202-246. crossref(new window)

4.
R. Curto and I. B. Jung, Quadratically hyponormal weighted shifts with two equal weights, Integral Equations Operator Theory, 37(2000), 208-231. crossref(new window)

5.
R. Curto and S. H. Lee, Quartically hyponormal weighted shifts need not be 3- hyponormal, J. Math. Anal. Appl., 314(2006), 455-463. crossref(new window)

6.
R. Curto and M. Putinar, Nearly subnormal operators and moment problems, J. Funct. Anal., 115(1993), 480-497. crossref(new window)

7.
G. Exner, I. B. Jung, and S. S. Park, Weakly n-hyponormal weighted shifts and their examples, Integral Equations Operator Theory, 54(2006), 215-233. crossref(new window)

8.
I. B. Jung and S. S. Park, Quadratically hyponormal weighted shifts and their exam- ples, Integral Equations Operator Theory, 36(2000), 480-498. crossref(new window)

9.
I. B. Jung and S. S. Park, Cubically hyponormal weighted shifts and their examples, J. Math. Anal. Appl., 247(2000), 557-569. crossref(new window)

10.
Wolfram Research, Inc., Mathematica, Version 8.0, Wolfram Research Inc., Cham- paign, IL, 2010.