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Krylov subspaces associated with higher-order linear dynamical systems

Roland W. Freund
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Abstract

A standard approach to model reduction of large-scale higher-order linear dynamical systems is to rewrite the system as an equivalent first-order system and then employ Krylov-subspace techniques for model reduction of first-order systems. This paper presents some results about the structure of the block-Krylov subspaces induced by the matrices of such equivalent first-order formulations of higher-order systems. Two general classes of matrices, which exhibit the key structures of the matrices of first-order formulations of higher-order systems, are introduced. It is proved that for both classes, the block-Krylov subspaces induced by the matrices in these classes can be viewed as multiple copies of certain subspaces of the state space of the original higher-order system.

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Roland W. Freund. 2005-01-27. Krylov subspaces associated with higher-order linear dynamical systems. https://arxiv.org/abs/math/0501484

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