Perturbation Theory, M-essential Spectra of 2⨯2 Operator Matrices and Application to Transport Operators
Aref Jeribi, Nedra Moalla, Sonia Yengui · Journal of Mathematics and Applications · 2021
In this article we give some results on perturbation theory of 2 × 2 block operator matrices on the product of Banach spaces.Furthermore, we investigate their M -essential spectra.Finally, we apply the obtained results to determine the M -essential spectra of two group transport operators with general boundary conditions in the Banach space L p ([-a, a] × [-1, 1]) × L p ([-a, a] × [-1, 1]), p ≥ 1 and a > 0.