Pick matrices and comparative stability

Description:  Complex interpolation (Nevanlinna-Pick or Schur-Caratheodory type) can be explained from several points of view, and I will offer yet another one: comparative stability. Here, given two (complex or real) matrices A,B, the question is to verify whether every Lyapunov factor for A is a Lyapunov factor for B (we say that H is a Lyapunov factor for X if X^TH+HX is positive semi-definite). The Pick matrix comes out here as the right hand side HA+AH for a very special matrix. Area(s): Date:  2005-11-02 Start Time:   14:30 Speaker:  Nir Cohen (UNICAMP, Brasil) Place:  5.5 Research Groups: -Algebra and Combinatorics See more:   <Main>