Spectral properties of perturbed linear operators and their application to infinite matrices
Spectral properties of perturbed linear operators and their application to infinite matrices
In this paper, upper bounds for the difference between the eigenvalues and the eigenvectors of a closed linear operator <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper D"> <mml:semantics> <mml:mi>D</mml:mi> <mml:annotation encoding="application/x-tex">D</mml:annotation> </mml:semantics> </mml:math> </inline-formula> and those of <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper D plus upper F"> <mml:semantics> <mml:mrow> <mml:mi>D</mml:mi> <mml:mo>+</mml:mo> <mml:mi>F</mml:mi> </mml:mrow> …