{ "id": "1202.6402", "version": "v1", "published": "2012-02-28T22:37:25.000Z", "updated": "2012-02-28T22:37:25.000Z", "title": "Spectral stability of periodic wave trains of the Korteweg-de Vries/Kuramoto-Sivashinsky equation in the Korteweg-de Vries limit", "authors": [ "Mathew A. Johnson", "Pascal Noble", "L. Miguel Rodrigues", "Kevin Zumbrun" ], "comment": "52 pages, 4 figures", "categories": [ "math.AP", "math.CA", "math.SP" ], "abstract": "We study the spectral stability of a family of periodic wave trains of the Korteweg-de Vries/Kuramoto-Sivashinsky equation $ \\partial_t v+v\\partial_x v+\\partial_x^3 v+\\delta(\\partial_x^2 v +\\partial_x^4 v)=0$, $\\delta>0$, in the Korteweg-de Vries limit $\\delta\\to 0$, a canonical limit describing small-amplitude weakly unstable thin film flow. More precisely, we carry out a rigorous singular perturbation analysis reducing the problem to the evaluation for each Bloch parameter $\\xi\\in [0,2\\pi]$ of certain elliptic integrals derived formally (on an incomplete set of frequencies/Bloch parameters, hence as necessary conditions for stability) and numerically evaluated by Bar and Nepomnyashchy \\cite{BN}, thus obtaining, up to machine error, complete conclusions about stability. The main technical difficulty is in treating the large-frequency and small Bloch-parameter regimes not studied by Bar and Nepomnyashchy \\cite{BN}, which requires techniques rather different from classical Fenichel-type analysis. The passage from small-$\\delta$ to small-$\\xi$ behavior is particularly interesting, using in an essential way an analogy with hyperbolic relaxation at the level of the Whitham modulation equations.", "revisions": [ { "version": "v1", "updated": "2012-02-28T22:37:25.000Z" } ], "analyses": { "keywords": [ "korteweg-de vries/kuramoto-sivashinsky equation", "korteweg-de vries limit", "periodic wave trains", "spectral stability", "unstable thin film flow" ], "note": { "typesetting": "TeX", "pages": 52, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2012arXiv1202.6402J" } } }