An extended nonsymmetric block Lanczos method for model reduction in large scale dynamical systems

In this paper, we propose an extended block Krylov process to construct two biorthogonal bases for the extended Krylov subspaces (mathbb {K}_{m}^e(A,V)) and (mathbb {K}_{m}^e(A^{T},W)), where (A in mathbb {R}^{n times n}) and (V,~W in mathbb {R}^{n times p}). After deriving some new theoretical results and algebraic properties, we apply the proposed algorithm with moment matching techniques for model reduction in large scale dynamical systems. Numerical experiments for large and sparse problems are given to show the efficiency of the proposed method.