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Xin Zhou

Professor Emeritus of Mathematics
Mathematics
Box 90320, Durham, NC 27708-0320
PO Box 90320, Durham, NC 27708

Selected Publications


Janossy densities for unitary ensembles at the spectral edge

Journal Article International Mathematics Research Notices · December 1, 2008 For a broad class of unitary ensembles of random matrices, we demonstrate the universal nature of the Janossy densities of eigenvalues near the spectral edge, providing a different formulation of the probability distributions of the limiting second, third, ... Full text Cite

Rational functions with a general distribution of poles on the real line orthogonal with respect to varying exponential weights: I

Journal Article Mathematical Physics Analysis and Geometry · November 1, 2008 Orthogonal rational functions are characterized in terms of a family of matrix Riemann-Hilbert problems on ℝ, and a related family of energy minimisation problems is presented. Existence, uniqueness, and regularity properties of the equilibrium measures wh ... Full text Cite

Asymptotics of laurent polynomials of odd degree orthogonal with respect to varying exponential weights

Journal Article Constructive Approximation · March 1, 2008 Let Λ ℝ denote the linear space over ℝ spanned by zk k ℤ. Define the (real) inner product Ċ,Ċ L : Λ ℝ× Λ ℝ ℝ, (f,g) ∫ℝ f(s)g(s) exp(- N V(s)) ds, N ℕ, where V satisfies: (i) V is real analytic on ℝ 0; ... Full text Cite

Asymptotics of recurrence relation coefficients, hankel determinant ratios, and root products associated with laurent polynomials orthogonal with respect to varying exponential weights

Journal Article Acta Applicandae Mathematicae · January 1, 2008 Let Λℝ denote the linear space over ℝ spanned by z k , k ∈ ℤ. Define the real inner product 〈 .,.〉 L : Λℝ×Λℝ→ℝ, (f,g)∫ℝ}f(s)g(s)exp (-{N}V(s)){d}s, N ∈, where V satisfies: (i) V is real anal ... Full text Cite

Semiclassical focusing nonlinear schrödinger equation i: Inverse scattering map and its evolution for radiative initial data

Journal Article International Mathematics Research Notices · December 1, 2007 We consider the semiclassical limit for the focusing nonlinear (cubic) Schrödinger Equation (NLS) in the pure radiational case. We present a method of reconstructing the leading order terms of the solitonless initial data and of its evolution for a wide cl ... Full text Cite

The Widom-Dyson constant for the gap probability in random matrix theory

Journal Article Journal of Computational and Applied Mathematics · May 1, 2007 In the bulk scaling limit for the Gaussian Unitary Ensemble in random matrix theory, the probability that there are no eigenvalues in the interval (0, 2 s) is given by Ps = det (I - Ks), where Ks is the trace-class operator ... Full text Cite

Asymptotics of Laurent polynomials of even degree orthogonal with respect to varying exponential weights

Journal Article International Mathematics Research Papers · October 18, 2006 Let Λℝ denote the linear space over ℝ spanned by zk, k ∈ ℤ. Define the real inner product (with varying exponential weights) 〈̇,̇〉ℒ : ΛRdbl; x ΛRdbl;. → ℝ, (f, g) ∫ℝ f(s)g(s) exp(-NV(s))ds, N ∈ ℕ, where ... Full text Cite

The Widpm-Dyson constant for the gap probability in random matrix theory

Journal Article a special edition of the Journal of Computational and Applied Mathematics · 2006 Cite

On the long-time limit of semiclassical (zero dispersion limit) solutions of the focusing nonlinear Schrödinger equation: Pure radiation case

Journal Article Communications on Pure and Applied Mathematics · January 1, 2006 In a previous paper [13] we calculated the leading-order term q 0(x, t, ε) of the solution of q(x, t, ε), the focusing nonlinear (cubic) Schrödinger (NLS) equation in the semiclassical limit (ε → 0) for a certain one-parameter family of initial ... Full text Cite

On semiclassical (zero dispersion limit) solutions of the focusing nonlinear Schrödinger equation

Journal Article Communications on Pure and Applied Mathematics · July 1, 2004 We calculate the leading-order term of the solution of the focusing nonlinear (cubic) Schrödinger equation (NLS) in the semiclassical limit for a certain one-parameter family of initial conditions. This family contains both solitons and pure radiation. In ... Full text Cite

Long-Time Asymptotics for Solutions of the NLS Equation with Initial Data in a Weighted Sobolev Space

Journal Article Communications on Pure and Applied Mathematics · August 1, 2003 Full text Cite

Interacting domain walls in an easy-plane ferromagnet

Journal Article Physical Review B Condensed Matter and Materials Physics · May 1, 2002 The Landau-Lifshitz equation for an anisotropic (easy-plane) ferromagnet is formulated as a Riemann-Hilbert problem on a Riemann surface of the spectral parameter. Exact multiple domain wall solutions can be obtained in a systematic and exhaustive manner b ... Full text Cite

A priori Lp-estimates for solutions of Riemann-Hilbert problems

Journal Article International Mathematics Research Notices · January 1, 2002 Full text Cite

A riemann-Hilbert approach to asymptotic questions for orthogonal polynomials

Journal Article Journal of Computational and Applied Mathematics · August 1, 2001 A few years ago the authors introduced a new approach to study asymptotic questions for orthogonal polynomials. In this paper we give an overview of our method and review the results which have been obtained in Deift et al. (Internat. Math. Res. Notices (1 ... Full text Cite

Optimal tail estimates for directed last passage site percolation with geometric random variables

Journal Article Advances in Theoretical and Mathematical Physics · January 1, 2001 In this paper, we obtain optimal uniform lower tail estimates for the probability distribution of the properly scaled length of the longest up/right path of the last passage site percolation model considered by Johansson in [12]. The estimates are used to ... Full text Cite

Strong asymptotics of orthogonal polynomials with respect to exponential weights

Journal Article Communications on Pure and Applied Mathematics · January 1, 1999 We consider asymptotics of orthogonal polynomials with respect to weights w(x)dx = e-Q(x)dx on the real line, where Q(x) = Σ2mk=0qkxk, q2m > 0, denotes a polynomial of even order with positive leading ... Full text Cite

Uniform asymptotics for polynomials orthogonal with respect to varying exponential weights and applications to universality questions in random matrix theory

Journal Article Communications on Pure and Applied Mathematics · January 1, 1999 We consider asymptotics for orthogonal polynomials with respect to varying exponential weights wn(x)dx = e-nV(x)dx on the line as n → ∞. The potentials V are assumed to be real analytic, with sufficient growth at infinity. The princip ... Full text Cite

Long-time asymptotics for the pure radiation solution of the sine-Gordon equation

Journal Article Communications in Partial Differential Equations · January 1, 1999 Full text Cite

Nonlinear magnetization dynamics of the classical ferromagnet with two single-ion anisotropies in an external magnetic field

Journal Article Physical Review B Condensed Matter and Materials Physics · January 1, 1999 By using a stereographic projection of the unit sphere of magnetization vector onto a complex plane for the equations of motion, the effect of an external magnetic field for integrability of the system is discussed. The properties of the Jost solutions and ... Full text Cite

On the algebro-geometric integration of the Schlesinger equations

Journal Article Communications in Mathematical Physics · January 1, 1999 A new approach to the construction of isomonodromy deformations of 2 × 2 Fuchsian systems is presented. The method is based on a combination of the algebro-geometric scheme and Riemann-Hilbert approach of the theory of integrable systems. For a given numbe ... Full text Cite

L2-Sobolev space bijectivity of the scattering and inverse scattering transforms

Journal Article Communications on Pure and Applied Mathematics · January 1, 1998 Full text Cite

An extension of the steepest descent method for Riemann-Hilbert problems: the small dispersion limit of the Korteweg-de Vries (KdV) equation.

Journal Article Proceedings of the National Academy of Sciences of the United States of America · January 1998 This paper extends the steepest descent method for Riemann-Hilbert problems introduced by Deift and Zhou in a critical new way. We present, in particular, an algorithm, to obtain the support of the Riemann-Hilbert problem for leading asymptotics. Applying ... Full text Cite

L2-Sobolev space bijectivity of the scattering and inverse scattering transforms

Journal Article Communications on Pure and Applied Mathematics · 1998 Cite

New Results in Small Dispersion KdV by an Extension of the Steepest Descent Method for Riemann-Hilbert Problems

Journal Article International Mathematics Research Notices · December 1, 1997 Cite

Asymptotics for Polynomials Orthogonal with Respect to Varying Exponential Weights

Journal Article International Mathematics Research Notices · December 1, 1997 Cite

Strong regularizing effect of integrable systems

Journal Article Communications in Partial Differential Equations · January 1, 1997 Full text Cite

The toda rarefaction problem

Journal Article Communications on Pure and Applied Mathematics · January 1, 1996 In the Toda shock problem (see [7], [11], [8], and also [3]) one considers a driving particle moving with a fixed velocity 2a and impinging on a one-dimensional semi-infinite lattice of particles, initially equally spaced and at rest, and interacting with ... Full text Cite

Inverse scattering transform for systems with rational spectral dependence

Journal Article Journal of Differential Equations · January 20, 1995 We characterize a class of first-order systems for which the inverse scattering problems can be formulated as matrix Riemann-Hilbert problems. For this class complete direct and inverse scattering results are obtained. © 1995 Academic Press, Inc. ... Full text Cite

Asymptotics for the painlevé II equation

Journal Article Communications on Pure and Applied Mathematics · January 1, 1995 Full text Cite

Long-time asymptotics for integrable systems. Higher order theory

Journal Article Communications in Mathematical Physics · October 1, 1994 The authors show how to obtain the full asymptotic expansion for solutions of integrable wave equations to all orders, as t→∞. The method is rigorous and systematic and does not rely on an a priori ansatz for the form of the solution. © 1994 Springer-Verla ... Full text Cite

The collisionless shock region for the long‐time behavior of solutions of the KdV equation

Journal Article Communications on Pure and Applied Mathematics · January 1, 1994 The authors further develop the nonlinear steepest descent method of [5] and [6] to give a full description of the collisionless shock region for solutions of the KdV equation with decaying initial data. © 1994 John Wiley & Sons, Inc. Copyright © 1994 Wile ... Full text Cite

On the solvability of Painleve I, III and V

Journal Article Inverse Problems · December 1, 1992 As rigorous methodology for studying the Riemann-Hilbert problems associated with certain integrable nonlinear ODEs was introduced in 1992 by Fokas and Zhou, and was used to investigate Painleve II and Painleve IV equations. Here the authors apply this met ... Full text Cite

On the solvability of Painlevé II and IV

Journal Article Communications in Mathematical Physics · March 1, 1992 We introduce a rigorous methodology for studying the Riemann-Hilbert problems associated with certain integrable nonlinear ordinary differential equations. For concreteness we investigate the Painlevé II and Painlevé IV equations. We show that the Cauchy p ... Full text Cite

A steepest descent method for oscillatory Riemann-Hilbert problems

Journal Article Bulletin of the American Mathematical Society · January 1, 1992 Full text Cite

Direct and inverse scattering on the line with arbitrary singularities

Journal Article Communications on Pure and Applied Mathematics · January 1, 1991 Full text Cite

Inverse scattering transform for the time dependent Schrödinger equation with applications to the KPI equation

Journal Article Communications in Mathematical Physics · March 1, 1990 For the direct-inverse scattering transform of the time dependent Schrödinger equation, rigorous results are obtained based on an opertor-triangular-factorization approach. By viewing the equation as a first order operator equation, similar results as for ... Full text Cite

Direct and inverse scattering transforms with arbitrary spectral singularities

Journal Article Communications on Pure and Applied Mathematics · January 1, 1989 Full text Cite