{ "id": "1610.05546", "version": "v1", "published": "2016-10-18T11:41:41.000Z", "updated": "2016-10-18T11:41:41.000Z", "title": "The Muskat problem in 2D: equivalence of formulations, well-posedness, and regularity results", "authors": [ "Bogdan-Vasile Matioc" ], "comment": "40 pages", "categories": [ "math.AP" ], "abstract": "In this paper we consider the Muskat problem describing the motion of two unbounded immiscible fluid layers with equal viscosities in vertical or horizontal two-dimensional geometries. We first prove that the mathematical model can be formulated as an evolution problem for the sharp interface separating the two fluids, which turns out to be, in a suitable functional analytic setting, quasilinear and of parabolic type. Based upon these properties, we then establish the local well-posedness of the problem for arbitrary large initial data and show that the solutions become instantly real-analytic in time and space. Our method allows us to choose the initial data in the class $H^s,$ $s\\in(3/2,2)$, when neglecting surface tension, respectively in $H^s,$ $s\\in(2,3),$ when surface tension effects are included. Besides, we provide new criteria for the global existence of solutions.", "revisions": [ { "version": "v1", "updated": "2016-10-18T11:41:41.000Z" } ], "analyses": { "subjects": [ "35R37", "35K59", "35K93", "35Q35", "42B20" ], "keywords": [ "muskat problem", "regularity results", "well-posedness", "formulations", "equivalence" ], "note": { "typesetting": "TeX", "pages": 40, "language": "en", "license": "arXiv", "status": "editable" } } }