A complete pair of solvents of a quadratic matrix pencil

V. G. Kurbatov; I. V. Kurbatova

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arXiv · 2405.07210

A complete pair of solvents of a quadratic matrix pencil

V. G. Kurbatov·I. V. Kurbatova

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Abstract

Let $B$ and $C$ be square complex matrices. The differential equation \begin{equation*} x''(t)+Bx'(t)+Cx(t)=f(t) \end{equation*} is considered. A solvent is a matrix solution $X$ of the equation $X^2+BX+C=\mathbf0$. A pair of solvents $X$ and $Z$ is called complete if the matrix $X-Z$ is invertible. Knowing a complete pair of solvents $X$ and $Z$ allows us to reduce the solution of the initial value problem to the calculation of two matrix exponentials $e^{Xt}$ and $e^{Zt}$. The problem of finding a complete pair $X$ and $Z$, which leads to small rounding errors in solving the differential equation, is discussed.

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V. G. Kurbatov, I. V. Kurbatova. 2024-05-12. A complete pair of solvents of a quadratic matrix pencil. https://arxiv.org/abs/2405.07210

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