2024/10/16 by Ghada Shuker Jameel, Jameel, Ghada Shuker, Karl Michael Schmidt +1
Computer Science · Mathematics · #34L40 #47A55 #47B28 #81Q15 #Advanced Mathematical Modeling in Engineering #Differential Equations and Numerical Methods #FOS: Mathematics #Spectral Theory (math.SP) #Spectral Theory in Mathematical Physics
paper · pdf · doi:10.48550/arxiv.2410.12467
openalex publication_date 2024/10/16 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We characterise regions in the complex plane that contain all non-embedded eigenvalues of a perturbed periodic Dirac operator on the real line with real-valued periodic potential and a generally non-symmetric matrix-valued perturbation V . We show that the eigenvalues are located close to the end-points of the spectral bands for small V in L1(R)2x2 , but only close to the spectral bands as a whole for small V in Lp(R)2x2 , p > 1. As auxiliary results, we prove the relative compactness of matrix multiplication operators in L2p(R)2x2 with respect to the periodic operator under minimal hypotheses, and find the asymptotic solution of the Dirac equation on a finite interval for spectral parameters with large imaginary part.