Singular perturbation theory for systems of differential equations in the case of multiple spectrum of the limit operator. I, II

A method is studied for constructing a regularized asymptotic expression for the solution of a Cauchy problem in the case of a multiple spectrum. The paper consists of two parts. The first part deals with the case when the operator is similar to a single Jordan cell, and the second with the case when the operator is similar to an operator with several Jordan cells. In both cases the structure matrix does not have degeneracies. The structure of a fundamental system of solutions is presented.
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