Writing the matrix adjoint as a rational function in the matrix can be interesting

Writing the matrix adjoint as a rational function in the matrix can be interesting

Thu, 27/10/2011
14:00 		Prof Joerg Liesen (Technical University of Berlin) Computational Mathematics and Applications Add to calendar Gibson Grd floor SR
Writing the matrix adjoint as a rational function in the matrix can be interesting
We will study the question of whether the adjoint of a given matrix can be written as a rational function in the matrix. After showing necessary and sufficient conditions, rational interpolation theory will help to characterize the most important existing cases. Several topics related to our question will be explored. They range from short recurrence Krylov subspace methods to the roots of harmonic polynomials and harmonic rational functions. The latter have recently found interesting applications in astrophysics, which will briefly be discussed as well.