{ "id": "1810.04944", "version": "v1", "published": "2018-10-11T10:34:05.000Z", "updated": "2018-10-11T10:34:05.000Z", "title": "Coupled Mode Equations and Gap Solitons in Higher Dimensions", "authors": [ "Tomas Dohnal", "Lisa Wahlers" ], "comment": "27 pages, 6 figures", "categories": [ "math.AP", "math-ph", "math.MP", "nlin.PS" ], "abstract": "We study waves-packets in nonlinear periodic media in arbitrary ($d$) spatial dimension, modeled by the cubic Gross-Pitaevskii equation. In the asymptotic setting of small and broad waves-packets with $N\\in \\mathbb{N}$ carrier Bloch waves the effective equations for the envelopes are first order coupled mode equations (CMEs). We provide a rigorous justification of the effective equations. The estimate of the asymptotic error is carried out in an $L^1$-norm in the Bloch variables. This translates to a supremum norm estimate in the physical variables. In order to investigate the existence of gap solitons of the $d$-dimensional CMEs, we discuss spectral gaps of the CMEs. For $N=4$ and $d=2$ a family of time harmonic gap solitons is constructed formally asymptotically and numerically. Moving gap solitons have not been found for $d>1$ and for the considered values of $N$ due to the absence of a spectral gap in the standard moving frame variables.", "revisions": [ { "version": "v1", "updated": "2018-10-11T10:34:05.000Z" } ], "analyses": { "subjects": [ "35Q55", "35Q60", "35L71", "41A60" ], "keywords": [ "higher dimensions", "time harmonic gap solitons", "first order coupled mode equations", "spectral gap", "standard moving frame variables" ], "note": { "typesetting": "TeX", "pages": 27, "language": "en", "license": "arXiv", "status": "editable" } } }