EXPANSION PROBLEMS FOR HERMITION MATRICES WHILE MAINTAINING THE EIGENVALUES

다국어 초록 (Multilingual Abstract)

For given Hermition matrix A, in this paper, we will study the existence of an expansion Hermition matrix A of A while maintaining the eigenvalues of A. For any proper subset ｛λj1, λj2, … , λjk｝of the spectrum σ(A) = (λ1, λ2, …, λn) of A, we explicitly show the existence of an expansion A^ of A whose spectrum contains all λj1, λj2, … , λjk· Moreover, we show that there exists a 2-step expansion A of A whose spectrum contains all eigenvalues of A, that is, σ(A) ⊂ σ(A).

참고문헌 (Reference)

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