On indecomposable normal matrices in spaces with indefinite scalar product
Abstract
Finite dimensional linear spaces (both complex and real) with indefinite scalar product [.,.] are considered. Upper and lower bounds are given for the size of an indecomposable matrix that is normal with respect to this scalar product in terms of specific functions of v = min{v, v+}, where v, (v+) is the number of negative (positive) squares of the form [x,x]. All the bounds except for one are proved to be strict.
 Publication:

arXiv Mathematics eprints
 Pub Date:
 December 2005
 arXiv:
 arXiv:math/0512585
 Bibcode:
 2005math.....12585H
 Keywords:

 Mathematics  Functional Analysis;
 Mathematics  Rings and Algebras;
 47B50;
 46C20;
 47B15;
 47B40
 EPrint:
 9 pages