Skip to Main Content

Proceedings of the American Mathematical Society

Published by the American Mathematical Society since 1950, Proceedings of the American Mathematical Society is devoted to shorter research articles 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.

 

Most similarity orbits are strongly dense
HTML articles powered by AMS MathViewer

by D. W. Hadwin, E. A. Nordgren, Heydar Radjavi and Peter Rosenthal PDF
Proc. Amer. Math. Soc. 76 (1979), 250-252 Request permission

Abstract:

It is shown that the strong and weak closures of the similarity orbit of an operator on a Banach space always coincide, and a simple characterization of these closures is given. Whenever an operator is not the sum of a scalar and a finite rank operator, its similarity orbit is strongly dense in the set of all bounded linear operators.
References
  • P. Enflo, On the invariant subspace problem in Banach spaces, Séminaire Maurey–Schwartz (1975–1976) Espaces $L^{p}$, applications radonifiantes et géométrie des espaces de Banach, Exp. Nos. 14-15, Centre Math., École Polytech., Palaiseau, 1976, pp. 7. MR 0473871
  • Donald W. Hadwin, An operator-valued spectrum, Indiana Univ. Math. J. 26 (1977), no. 2, 329–340. MR 428089, DOI 10.1512/iumj.1977.26.26025
  • —, Approximate equivalence and completely positive maps, preprint, 1978. D. W. Hadwin, E. Nordgren, Heydar Radjavi and Peter Rosenthal, An operator not satisfying Lomonosov’s hypothesis, preprint, 1978.
  • P. R. Halmos, Irreducible operators, Michigan Math. J. 15 (1968), 215–223. MR 231233
  • Paul R. Halmos, A Hilbert space problem book, D. Van Nostrand Co., Inc., Princeton, N.J.-Toronto, Ont.-London, 1967. MR 0208368
  • Domingo A. Herrero, Closure of similarity orbits of Hilbert space operators. I, Rev. Un. Mat. Argentina 27 (1976), no. 4, 244–260 (Spanish). MR 512768
  • —, Closure of similarity orbits of Hilbert space operators. V. Essentially BQT operators (preprint).
  • Dan Voiculescu, A non-commutative Weyl-von Neumann theorem, Rev. Roumaine Math. Pures Appl. 21 (1976), no. 1, 97–113. MR 415338
Similar Articles
  • Retrieve articles in Proceedings of the American Mathematical Society with MSC: 47A65, 47A15
  • Retrieve articles in all journals with MSC: 47A65, 47A15
Additional Information
  • © Copyright 1979 American Mathematical Society
  • Journal: Proc. Amer. Math. Soc. 76 (1979), 250-252
  • MSC: Primary 47A65; Secondary 47A15
  • DOI: https://doi.org/10.1090/S0002-9939-1979-0537082-1
  • MathSciNet review: 537082