F eb 2 01 3 Exceptional Points , Nonnormal Matrices , Hierarchy of Spin Matrices and an Eigenvalue Problem
نویسنده
چکیده
Kato [1] (see also Rellich [2]) introduced exceptional points for singularities appearing in the perturbation theory of linear operators. Afterwards exceptional points and energy level crossing have been studied for hermitian Hamilton operators [3, 4, 5, 6, 7, 8, 9, 10] and non-hermitian Hamilton operators [11, 12, 13, 14, 15, 16] by many authors. Here we consider the finite dimensional Hilbert space C and the linear operators are n× n matrices over C.
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تاریخ انتشار 2013