Let T โ B(H) be an invertible operator with polar decomposition T = UP and B โ B(H) commute with T . In this paper we prove that |||P ฮป BUP 1-ฮป ||| |||BT |||, where ||| โข ||| is a weakly unitarily invariant norm on B(H) and 0 ฮป 1. As the consequence of this result, we have |||f (P ฮป UP 1-ฮป )||| |||f
On weakly unitarily invariant norm and the Aluthge transformation
โ Scribed by K. Okubo
- Publisher
- Elsevier Science
- Year
- 2003
- Tongue
- English
- Weight
- 85 KB
- Volume
- 371
- Category
- Article
- ISSN
- 0024-3795
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โฆ Synopsis
In this paper we show that
where T โ B(H), ||| โข ||| is a semi-norm on B(H) which satisfies some conditions, T = UP (polar decomposition), 0 ฮป 1 and f is a polynomial. As a consequence of this fact, we will show that some semi-norms ||| โข ||| including the ฯ-radii (0 < ฯ 2) satisfy the inequality |||f (P ฮป UP 1-ฮป )||| |||f (T )|||. We also give some related results.
๐ SIMILAR VOLUMES
## Abstract In this paper, by generalizing the ideas of the (generalized) polar decomposition to the weighted polar decomposition and the unitarily invariant norm to the weighted unitarily invariant norm, we present some perturbation bounds for the generalized positive polar factor, generalized non