Abstract (EN):
Let A ¿ FnXn, B ¿ FnXt, where F is an arbitrary field. In this paper, the possible characteristic polynomials of [A B], when some of its columns are prescribed and the other columns vary, are described. The characteristic polynomial of [A B] is defined as the largest determinantal divisor (or the product of the invariant factors) of [xI n - A - B]. This result generalizes a previous theorem by H. Wimmer which studies the same problem when t = 0. As a consequence, it is extended to arbitrary fields a result, already proved for infinite fields, that describes all the possible characteristic polynomials of a square matrix when an arbitrary submatrix is fixed and the other entries vary. Finally, applications to the stabilization and observability of linear systems by state feedback are studied.
Language:
English
Type (Professor's evaluation):
Scientific
No. of pages:
12