ArticleOriginal scientific text

Title

Maps on matrices that preserve the spectral radius distance

Authors 1, 2, 3

Affiliations

  1. Indian Statistical Institute, New Delhi 110 016, India
  2. Department of Mathematics, University of Ljubljana, Jadranska 19, 1000 Ljubljana, Slovenia
  3. Department of Mathematics and Statistics, University of Victoria, Victoria, B.C., Canada V8W 3P4

Abstract

Let ϕ be a surjective map on the space of n×n complex matrices such that r(ϕ(A)-ϕ(B))=r(A-B) for all A,B, where r(X) is the spectral radius of X. We show that ϕ must be a composition of five types of maps: translation, multiplication by a scalar of modulus one, complex conjugation, taking transpose and (simultaneous) similarity. In particular, ϕ is real linear up to a translation.

Bibliography

  1. R. Bhatia and P. Šemrl, Approximate isometries on Euclidean spaces, Amer. Math. Monthly 104 (1997), 497-504.
  2. A. A. Jafarian and A. R. Sourour, Spectrum-preserving linear maps, J. Funct. Anal. 66 (1986), 255-261.
  3. M. Jerison, The space of bounded maps into a Banach space, Ann. of Math. 52 (1950), 307-327.
  4. S. Mazur et S. Ulam, Sur les transformations isométriques d'espaces vectoriels normés, C. R. Acad. Sci. Paris 194 (1932), 946-948.
  5. P. Šemrl, Linear maps that preserve the nilpotent operators, Acta Sci. Math. (Szeged) 61 (1995), 523-534.
Pages:
99-110
Main language of publication
English
Received
1997-06-27
Published
1999
Exact and natural sciences