{ "id": "1605.04178", "version": "v1", "published": "2016-05-13T13:44:04.000Z", "updated": "2016-05-13T13:44:04.000Z", "title": "Nonlinear elliptic equations and systems with linear part at resonance", "authors": [ "Philip Korman" ], "comment": "17 pages", "journal": "Electronic Journal of Differential Equations, Vol. 2016 (2016), No. 67, pp. 1--17", "categories": [ "math.AP", "math.CA" ], "abstract": "The famous result of Landesman and Lazer [10] dealt with resonance at a simple eigenvalue. Soon after publication of [10], Williams [14] gave an extension for repeated eigenvalues. The conditions in Williams [14] are rather restrictive, and no examples were ever given. We show that seemingly different classical result by Lazer and Leach [11], on forced harmonic oscillators at resonance, provides an example for this theorem. The article by Williams [14] also contained a shorter proof. We use a similar approach to study resonance for $2 \\times 2$ systems. We derive conditions for existence of solutions, which turned out to depend on the spectral properties of the linear part.", "revisions": [ { "version": "v1", "updated": "2016-05-13T13:44:04.000Z" } ], "analyses": { "subjects": [ "35J61", "35J47" ], "keywords": [ "nonlinear elliptic equations", "linear part", "study resonance", "similar approach", "shorter proof" ], "tags": [ "journal article" ], "note": { "typesetting": "TeX", "pages": 17, "language": "en", "license": "arXiv", "status": "editable" } } }