Indian Statistical Institute, 7, S. J. S. Sansanwal Marg, New Delhi -- 110016, India ; Department of Mathematics, University of California at Berkeley, Berkeley, California 94720
Abstract:
A well-known result on spectral variation of a Hermitian matrix due to Mirsky is the following: Let and be two Hermitian matrices, and let and be their eigenvalues arranged in ascending order. Then for any unitarily invariant norm . In this paper, we generalize this to the perturbation theory for diagonalizable matrix pencils with real spectra. The much studied case of definite pencils is included in this.