Year: 2026
Type: article
Abstract: We analyze the spectral stability of travelling waves in a δ-regularized dissipative sine-Gordon equation modelling refined long Josephson junction dynamics. Linearization about a wave yields a singularly perturbed fourth-order spectral problem with intrinsic slow–fast spatial structure. Using an Evans-function formulation on a domain of consistent spatial splitting, we establish a local factorization separating slow and fast modes and prove that the δ-induced fast subsystem remains uniformly hyperbolic and does not generate an additional point spectrum near λ=0. Hence, the local point spectrum coincides with that of the classical dissipative sine-Gordon equation. Numerical computations of the essential spectrum and Evans winding numbers confirm the analysis and show that the higher-order terms enhance high-frequency damping without altering low-frequency spectral stability.
Source: Symmetry
DOI: 10.3390/sym18030512
Author: Vassilios M. Rothos
Institution: Aristotle University of Thessaloniki
Language: English
Subfield: Mathematical Physics
Field: Mathematics
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,896
OpenAlex ID: W7138152225
