Hostname: page-component-cd9895bd7-mkpzs Total loading time: 0 Render date: 2024-12-30T22:21:57.947Z Has data issue: false hasContentIssue false

ALL PRIMES HAVE CLOSED RANGE

Published online by Cambridge University Press:  14 June 2001

C. J. READ
Affiliation:
Faculty of Mathematics, University of Leeds, Leeds LS2 9JT, [email protected]
Get access

Abstract

In this paper, we show first that any prime (or semiprime) element of a commutative Banach algebra must have closed range. As a corollary, we find that in a commutative radical Banach algebra, all primes are zero divisors; indeed, all semiprimes are zero divisors (see below for the definition of semiprimeness). Our result is also true of a semiprime that is in the centre of a noncommutative Banach algebra.

The proof is fairly simple and entertaining, and we obtain a result that is helpful for the ambitious classification of elements in commutative radical Banach algebras being attempted by Marc Thomas. It is also related to the unbounded Kleinecke–Shirov conjecture.

Type
NOTES AND PAPERS
Copyright
© The London Mathematical Society 2001

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)