{ "id": "1010.1223", "version": "v1", "published": "2010-10-06T18:35:27.000Z", "updated": "2010-10-06T18:35:27.000Z", "title": "Even order periodic operators on the real line", "authors": [ "Andrey Badanin", "Evgeny Korotyaev" ], "comment": "35 pages, 4 figures", "categories": [ "math-ph", "math.MP" ], "abstract": "We consider $2p\\ge 4$ order differential operator on the real line with a periodic coefficients. The spectrum of this operator is absolutely continuous and is a union of spectral bands separated by gaps. We define the Lyapunov function, which is analytic on a p-sheeted Riemann surface. The Lyapunov function has real or complex branch points. We prove the following results: (1) The spectrum at high energy has multiplicity two. (2) Endpoints of all gaps are periodic (or anti-periodic) eigenvalues or real branch points. (3) The spectrum of operator has an infinite number of open gaps and there exists only a finite number of non-real branch points for some specific coefficients (the generic case). (4) The asymptotics of the periodic, anti-periodic spectrum and branch points are determined at high energy.", "revisions": [ { "version": "v1", "updated": "2010-10-06T18:35:27.000Z" } ], "analyses": { "subjects": [ "47E05", "34L20" ], "keywords": [ "order periodic operators", "real line", "high energy", "lyapunov function", "complex branch points" ], "note": { "typesetting": "TeX", "pages": 35, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2010arXiv1010.1223B" } } }