Nosmas, Jean Clarence Approximations semi-classiques du spectre de systèmes différentiels asymptotiques. (French) Zbl 0535.58040 C. R. Acad. Sci., Paris, Sér. I 295, 253-256 (1982). The author generalizes results on spectral properties of selfadjoint asymptotic differential equations [see the author, Journ. ”Equations Dériv. Partielles”, St.-Jean-De-Monts 1982, Conf. No.14 (1982; Zbl 0497.58023)] to asymptotic systems. At first a brief survey on the symbol calculus is given. Then this calculus is adapted to selfadjoint asymptotic differential systems. The author derives asymptotic approximations of their spectrum. As an example a (2\(\times 2)-system\), namely the reduced Dirac-equation for the atom with one electron in a constant magnetic field, is treated. Reviewer: K.H.Jansen Cited in 3 Documents MSC: 58J50 Spectral problems; spectral geometry; scattering theory on manifolds 58J40 Pseudodifferential and Fourier integral operators on manifolds 35P15 Estimates of eigenvalues in context of PDEs Keywords:symbol calculus; spectral properties of asymptotic differential systems; Dirac-equation Citations:Zbl 0497.58023 × Cite Format Result Cite Review PDF