{ "id": "math/9201261", "version": "v1", "published": "1992-01-01T00:00:00.000Z", "updated": "1992-01-01T00:00:00.000Z", "title": "A steepest descent method for oscillatory Riemann-Hilbert problems", "authors": [ "Percy Deift", "Xin Zhou" ], "comment": "6 pages. Abstract added in migration.", "journal": "Bull. Amer. Math. Soc. (N.S.) 26 (1992) 119-124", "categories": [ "math.AP" ], "abstract": "In this announcement we present a general and new approach to analyzing the asymptotics of oscillatory Riemann-Hilbert problems. Such problems arise, in particular, in evaluating the long-time behavior of nonlinear wave equations solvable by the inverse scattering method. We will restrict ourselves here exclusively to the modified Korteweg de Vries (MKdV) equation, $$y_t-6y^2y_x+y_{xxx}=0,\\qquad -\\infty