Skip to Main Content

Proceedings of the American Mathematical Society

Published by the American Mathematical Society, the Proceedings of the American Mathematical Society (PROC) is devoted to research articles of the highest quality in all areas of pure and applied mathematics.

ISSN 1088-6826 (online) ISSN 0002-9939 (print)

The 2020 MCQ for Proceedings of the American Mathematical Society is 0.85.

What is MCQ? The Mathematical Citation Quotient (MCQ) measures journal impact by looking at citations over a five-year period. Subscribers to MathSciNet may click through for more detailed information.

 

A simple example of a normal operator $T$ on a Banach space such that $r(T)<\Vert T\Vert$
HTML articles powered by AMS MathViewer

by Muneo Chō and Hiroyasu Yamaguchi PDF
Proc. Amer. Math. Soc. 108 (1990), 143 Request permission

Abstract:

Bonsall and Duncan’s book ([1, Theorem 25.6]) exhibits a normal element $h + ik$ of a Banach algebra such that $r(h + ik) < ||h + ik||$. In this paper, we will give a simpler example of a normal operator $T$ on a Banach space such that $r(T) < ||T||$.
References
Similar Articles
  • Retrieve articles in Proceedings of the American Mathematical Society with MSC: 47B15, 15A60, 47A10
  • Retrieve articles in all journals with MSC: 47B15, 15A60, 47A10
Additional Information
  • © Copyright 1990 American Mathematical Society
  • Journal: Proc. Amer. Math. Soc. 108 (1990), 143
  • MSC: Primary 47B15; Secondary 15A60, 47A10
  • DOI: https://doi.org/10.1090/S0002-9939-1990-0990417-2
  • MathSciNet review: 990417