Bibliography of articles on subnormal matrices
listed in chronological order

  1. P. R. Halmos, Subnormal operators and the subdiscrete topology, Internat. Ser. Numer. Math. 65, Birkhaüser, Basel, (1984), pp. 49­65.
  2. S. H. Friedberg and A. J. Insel, Hyponormal 2 x 2 matrices are subnormal, Linear Algebra Appl.   175:31­38 (1992).
  3. S. H. Friedberg and A. J. Insel, Characterizations of subnormal matrices, Linear Algebra Appl.   231:1­13 (1995).
  4. A. J. Insel, Levels of Subnormality, Linear Algebra Appl.   267:27­53 (1997).
  5. H. J. Woerdeman, Hermitian and Normal Completions, (Unpublished).

I would be very interested in communications and exchanges on this subject.