papers

Publications (99)

math-ph2024

Soliton resolution and asymptotic stability of -loop-soliton solutions for the Ostrovsky-Vakhnenko equation

Ruihong Ma, Engui Fan

The Ostrovsky-Vakhnenko (OV) equation \begin{align*} &u_{txx}-3κu_x+3u_xu_{xx}+uu_{xxx}=0 \end{align*} is a short wave model of the well-known Degasperis-Procesi equation and admi…

math.AP2026

Painlevé \uppercase\expandafter{\romannumeral34\relax} and collisionless shock in the defocusing NLS equation with step-like initial data in the transition regions

Engui Fan, Zhaoyu Wang, Yidan Zhang

We consider the Cauchy problem for the defocusing nonlinear Schrödinger (NLS) equation with step-like initial data. Using the nonlinear steepest descent method, we derive the long…

nlin.SI2014

Algebro-Geometric Solutions for the Kadomtsev-Petviashvili Hierarchy

Peng Zhao, Engui Fan

Based on the idea of symmetric constraint, we apply the Gesztesy-Holden's method to derive explicit representations of the Baker-Ahkiezer function of the KP hierarchy, from…

nlin.SI2013

Long-time asymptotic for the derivative nonlinear Schrödinger equation with step-like initial value

Jian Xu, Engui Fan

We consider the Cauchy problem for the Gerdjikov-Ivanov(GI) type of the derivative nonlinear Schrödinger (DNLS) equation: with…

math.AP2021

Long time asymptotics for the nonlocal mKdV equation with finite density initial data

Xuan Zhou, Engui Fan

In this paper, we consider the Cauchy problem for an integrable real nonlocal (also called reverse-space-time) mKdV equation with nonzero boundary conditions \begin{align*} &q_t(x,…

math-ph2024

A Riemann-Hilbert approach to the two-component modified Camassa-Holm equation

Kai Xu, Luman Ju, Engui Fan

In this paper, we develop a Riemann-Hilbert (RH) approach to the Cauchy problem for the two-component modified Camassa-Holm (2-mCH) equation based on its Lax pair. Further via a se…

math.AP2021

Long time asymptotics for the focusing nonlinear Schrödinger equation in the solitonic region with the presence of high-order discrete spectrum

Zhaoyu Wang, Meisen Chen, Engui Fan

In this paper, we use the steepest descent method to study the initial value problem for focusing nonlinear Schrödinger (fNLS) equation with non-generic weighted…

math-ph2024

Soliton Shielding of the focusing modified KdV equation

Ruihong Ma, Engui Fan

We consider soliton gas solutions of the modified Korteweg-de Vries (mKdV) equation, where the point spectrum of the condensate is located within a bounded domain in the upper half…

math.CA2015

Perturbed Hankel determinant, correlation functions and Painlevé equations

Min Chen, Yang Chen, Engui Fan

We continue with the study of the Hankel determinant, generated by a Pollaczek-Jacobi type w…

nlin.SI2011

On Negative Order KdV Equations

Zhijun Qiao, Engui Fan

In this paper, based on the regular KdV system, we study negative order KdV (NKdV) equations about their Hamiltonian structures, Lax pairs, infinitely many conservation laws, and e…

math.AP2022

Sobolev space bijectivity of the scattering-inverse scattering transforms related to defocusing Ablowitz-Ladik systems

Meisen Chen, Engui Fan, Jingsong He

In this paper, we establish -Sobolev space bijectivity of the inverse scattering transform related to the defocusing Ablowitz-Ladik system. On the one hand, in the direct prob…

math-ph2022

Large-time asymptotics to the focusing nonlocal modified Kortweg-de Vries equation with step-like boundary conditions

Taiyang Xu, Engui Fan

We investigate the large-time asymptotics of solution for the Cauchy problem of the nonlocal focusing modified Kortweg-de Vries (MKdV) equation with step-like initial data, i.e., $…

math.AP2022

The Fokas-Lenells equation on the line: Global well-posedness with solitons

Qiaoyuan Cheng, Engui Fan

In this paper, we prove the existence of global solutions in to the Fokas-Lenells (FL) equation on the line when the initial data includes…

math.AP2021

Long-time asymptotic behavior of the nonlocal nonlinear Schrödinger equation with initial potential in weighted sobolev space

Meisen Chen, Engui Fan

In this paper, we are going to investigate Cauchy problem for nonlocal nonlinear Schrödinger equation with the initial potential in weighted sobolev space $H^{1,1}(\mathb…

math.AP2022

Long time asymptotic behavior for the nonlocal mKdV equation in space-time solitonic regions-II

Xuan Zhou, Engui Fan

We study the long time asymptotic behavior for the Cauchy problem of an integrable real nonlocal mKdV equation with nonzero initial data in the solitonic regions \begin{align*} &q_…

math.AP2021

On the asymptotic stability of -soliton solutions of the three-wave resonant interaction equation

Yiling Yang, Engui Fan

The three-wave resonant interaction (three-wave) equation not only possesses matrix spectral problem, but also being absence of stationary phase points, which give rise…

math.AP2023

On the global existence for the modified Camassa-Holm equation via the inverse scattering method

Yiling Yang, Engui Fan, Yue Liu

In this paper, we address the existence of global solutions to the Cauchy problem of the modified Camassa-Holm (mCH) equation, which is known as a model for the unidirectional prop…

math.AP2022

A Riemann-Hilbert approach to existence of global solutions to the Fokas-Lenells equation on the line

Qiaoyuan Cheng, Engui Fan

We obtain the the existence of global solutions to the Cauchy problem of the Fokas-Lenells (FL) equation on the line \begin{align} &u_{xt}+αβ^2u-2iαβu_x-αu_{xx}-iαβ^2|u|^2u_…

nlin.SI2022

On the long-time asymptotics of the modified Camassa-Holm equation with step-like initial data

Yiling Yang, Gaozhan Li, Engui Fan

We study the long time asymptotic behavior for the Cauchy problem of the modified Camassa-Holm (mCH) equation with step-like initial data \begin{align} &m_{t}+\left(m\left(u^{2}-u_…

nlin.SI2013

Algebro-geometric solutions and their reductions for the Fokas-Lenells hierarchy

Peng Zhao, Engui Fan, Yu Hou

This paper is dedicated to provide theta function representations of algebro-geometric solutions for the Fokas-Lenells (FL) hierarchy through studying an algebro-geometric initial…

math.AP2023

Existence of global solutions for the modified Camassa-Holm equation with a nonzero background

Yiling Yang, Engui Fan, Yue Liu

Consideration in the present paper is the existence of global solutions for the modified Camassa-Holm (mCH) equation with a nonzero background initial value. The mCH equation is co…

math.AP2022

Existence of global solutions to the nonlocal Schrödinger equation on the line

Yi Zhao, Engui Fan

In this paper, we address the existence of global solutions to the Cauchy problem for the integrable nonlocal nonlinear Schrödinger (nonlocal NLS) equation with the initial data $…

nlin.SI2012

Long-time asymptotic for the derivative nonlinear Schrödinger equation with decaying initial value

Jian Xu, Engui Fan

We present a new Riemann-Hilbert problem formalism for the initial value problem for the derivative nonlinear Schrödinger (DNLS) equation on the line. We show that the solution of…

nlin.SI2012

The algebro-geometric solutions for the modified Camassa-Holm hierarchy

Yu Hou, Engui Fan, Zhijun Qiao

This paper is dedicated to provide theta function representation of algebro-geometric solutions and related crucial quantities for the modified Camassa-Holm (MCH) hierarchy through…

math.AP2025

Soliton resolution and asymptotic stability of -soliton solutions for the defocusing mKdV equation with a non-vanishing background

Zechuan Zhang, Taiyang Xu, Engui Fan

We analytically study the large-time asymptotics of the solution of the defocusing modified Korteweg-de Vries (mKdV) equation under a symmetric non-vanishing background, which supp…

nlin.SI2015

The GLM representation of the global relation for the two-component nonlinear Schrödinger equation on the interval

Jian Xu, Engui Fan

In a previous work, we show that the solution of the initial-boundary value problem for the two-component nonlinear Schrödinger equation on the finite interval can be expressed in…

nlin.SI2010

Binary Bell polynomials approach to the integrability of nonisospectral and variable-coefficient nonlinear equations

Engui Fan

Recently, Lembert, Gilson et al proposed a lucid and systematic approach to obtain bilinear Bäcklund transformations and Lax pairs for constant-coefficient soliton equations based…

nlin.SI2012

The Algebro-Geometric Solutions for the Ruijsenaars-Toda Hierarchy

Peng Zhao, Engui Fan, Yu Hou

We provide a detailed treatment of Ruijsenaars-Toda (RT) hierarchy with special emphasis on its the theta function representation of all algebro-geometric solutions. The basic tool…

math.AP2025

Long-time Asymptotics for the Ablowitz-Ladik system with present of solitons

Meisen Chen, Engui Fan, Zhaoyu Wang

We investigate the soliton resolution and Painlevé asymptotics for the focusing Ablowitz-Ladik system with the initial data in a discrete weighted space. First, we establ…

math-ph2017

Long-time asymptotic behavior for the complex short pulse equation

Jian Xu, Engui Fan

In this paper, we consider the initial value problem for the complex short pulse equation with a Wadati-Konno-Ichikawa type Lax pair. We show that the solution to the initial value…

nlin.SI2012

The coupled Schodinger hierarchy associated with third-order algebraic curves and algebro-geometric solutions

Yu Hou, Engui Fan

By introducing Lenard recursion equations, we derive a general coupled nonlinear Schdinger (CNLS) hierarchy associated with well-known Manakov system and Sasa-Sa…

nlin.SI2015

The Ostrovsky-Vakhnenko equation on the half-line: a Riemann-Hilbert approach

Jian Xu, Engui Fan

We analyze an initial-boundary value problem for the Ostrovsky-Vakhnenko equation on the half-line. This equation can be viewed as the short wave model for the Degasperis-Procesi (…

nlin.SI2019

Riemann-Hilbert approach to the modified nonlinear Schröinger equation with non-vanishing asymptotic boundary conditions

Yiling Yang, Engui Fan

The modified nonlinear Schrödinger (NLS) equation was proposed to describe the nonlinear propagation of the Alfven waves and the femtosecond optical pulses in a nonlinear single-m…

math.AP2023

Long-time asymptotic behavior of the Hunter-Saxton equation

Luman Ju, Kai Xu, Engui Fan

With -generalization of the Deift-Zhou steepest descent method, we investigate the long-time asymptotics of the solution to the Cauchy problem for the Hunter-Saxton…

nlin.SI2014

Algebro-geometric solutions for the two-component Hunter-Saxton hierarchy

Yu Hou, Engui Fan

This paper is dedicated to provide theta function representations of algebro-geometric solutions and related crucial quantities for the two-component Hunter-Saxton (HS2) hierarchy…

math-ph2018

Asymptotic Gap Probability Distributions of the Gaussian Unitary Ensembles and Jacobi Unitary Ensembles

Shulin Lyu, Yang Chen, Engui Fan

In this paper, we address a class of problems in unitary ensembles. Specifically, we study the probability that a gap symmetric about 0, i.e. is found in the Gaussian unit…

math.AP2020

Long-time asymptotic behavior of a mixed schrödinger equation with weighted Sobolev initial data

Qiaoyuan Cheng, Yiling Yang, Engui Fan

We apply steepest descent method to obtain sharp asymptotics for a mixed schrödinger equation $$…

nlin.SI2013

The Fokas method to the Sasa-Satsuma equation on the half-line

Jian Xu, Engui Fan

We present a Riemann-Hilbert problem formalism for the initial-boundary value problem for the Sasa-Satsuma(SS) equation: $iq_T+\frac{1}{2}q_{XX}+|q|^2q+i\eps (q_{XXX}+6|q|^2q_X+3q(…

nlin.SI2014

New Construction of Algebro-Geometric Solutions to the Modified Kadomtsev-Petviashvili Hierarchy

Peng Zhao, Engui Fan

We extend Gesztesy-Holden's method to 2+1 dimensional case to obtain a unified construction to the algebro-geometric solutions of the whole modified Kadomtsev-Petviashvili (mKP) hi…

math.CA2020

Critical edge behavior in the singularly perturbed Pollaczek-Jacobi type unitary ensemble

Zhaoyu Wang, Engui Fan

In this paper, we study the strong asymptotic for the orthogonal polynomials and universality associated with singularly perturbed Pollaczek-Jacobi type weight $$w_{p_J2}(x,t)=e^{-…

nlin.SI2012

The Algebro-Geometric Initial Value Problem for the Relativistic Lotka-Volterra Hierarchy and Quasi-Periodic Solutions

Peng Zhao, Engui Fan, Yu Hou

We provide a detailed treatment of relativistic Lotka-Volterra hierarchy and a kind of initial value problem with special emphasis on its the theta function representation of all a…

nlin.SI2012

The derivative nonlinear Schrodinger equation on the interval

Jian Xu, Engui Fan

We use the Fokas method to analyze the derivative nonlinear Schrödinger (DNLS) equation on the interval . Assuming that the solution $q(x…

math.AP2025

Existence of global solutions to the Fokas-Lenells equation with arbitrary spectral singularities

Yuan Li, Qiaoyuan Cheng, Engui Fan

We establish the global existence of solutions to the Fokas-Lenells equation for any initial data in a weighted Sobolev space .This resul…

math.AP2024

Orbital Stability of Soliton for the Derivative Nonlinear Schrödinger Equation in the Space

Yiling Yang, Engui Fan, Yue Liu

In this paper, we establish the orbital stability of the 1-soliton solution for the derivative nonlinear Schrödinger equation under perturbations in . We demonstr…

nlin.SI2021

Long time asymptotic behavior for the derivative Schrödinger equation with nonzero boundary conditions

Yiling Yang, Qiaoyuan Cheng, Engui Fan

In this paper, we apply steepest descent method to study the Cauchy problem for the derivative nonlinear Schrödinger equation with nonzero boundary conditions…

nlin.SI2014

A Riemann-Hilbert approach to the Harry-Dym equation on the line

Yu Xiao, Engui Fan

In this paper, we consider the Harry-Dym equation on the line with decaying initial value. The Fokas unified method is used to construct the solution of the Harry-Dym equation via…

math-ph2025

The Painlevé-type asymptotics of defocusing complex mKdV equation with finite density initial data

Lili Wen, Engui Fan

We consider the Cauchy problem for the defocusing complex mKdV equation with finite density initial data \begin{align*} &q_t+\frac{1}{2}q_{xxx}-3|q|^2q_{x}=0,\\ &q(x,0)=q_{0}(x) \s…

nlin.SI2010

Bilinear approach to the quasi-periodic wave solutions of supersymmetric equations in superspace

Engui Fan

We devise a lucid and straightforward way for explicitly constructing quasi-periodic wave solutions (also called multi-periodic wave solutions) of supersymmetric equations in super…

nlin.SI2019

The Sasa-Satsuma equation with non-vanishing boundary conditions

Lili Wen, Engui Fan

We concentrate on inverse scattering transformation for the Sasa-Satsuma equation with matrix spectral and nonzero boundary condition in this article. To circumvent mul…

math-ph2014

Similarity reductions and new nonlinear exact solutions for the 2D incompressible Euler equations

Engui Fan, Manwai Yuen

For the 2D and 3D Euler equations, their existing exact solutions are often in linear form with respect to variables x,y,z. In this paper, the Clarkson-Kruskal reduction method is…

math.AP2022

Long-time asymptotics for the focusing Fokas-Lenells equation in the solitonic region of space-time

Qiaoyuan Cheng, Engui Fan

We study the long-time asymptotic behavior of the focusing Fokas-Lenells (FL) equation $$ u_{xt}+αβ^2u-2iαβu_x-αu_{xx}-iαβ^2|u|^2u_x=0 \label{cs} $$ with generic initial dat…

nlin.SI2013

Leading-order temporal asymptotics of the Fokas-Lenells Equation without solitons

Jian Xu, Engui Fan

We use the Deift-Zhou method to obtain, in the solitonless sector, the leading order asymptotic of the solution to the Cauchy problem of the Fokas-Lenells equation as $t\ra+\infty$

nlin.SI2010

Generalized Super Bell Polynomials with Applications to Superymmetric Equations

Engui Fan, Y. C. Hon

In this paper, we introduce a class of new generalized super Bell polynomials on a superspace, explore their properties, and show that they are a natural and effective tool to syst…

math-ph2024

Soliton resolution and asymptotic stability of -solitons to the Degasperis-Procesi equation on the line

Xuan Zhou, Zhaoyu Wang, Engui Fan

The Degasperis-Procesi (DP) equation \begin{align} &u_t-u_{txx}+3κu_x+4uu_x=3u_x u_{xx}+uu_{xxx}, \nonumber \end{align} serving as a model delineating the propagation of shallow w…

math.AP2024

-Sobolev space bijectivity and existence of global solutions for the matrix nonlinear Schrödinger equations

Yuan Li, Xinhan Liu, Engui Fan

We consider the Cauchy problem to the general defocusing and focusing matrix nonlinear Schrödinger (NLS) equations with initial data allowing arbitrary-order poles and…

nlin.SI2012

The algebro-geometric solutions for Degasperis-Procesi hierarchy

Yu Hou, Peng Zhao, Engui Fan +1

Though completely integrable Camassa-Holm (CH) equation and Degasperis-Procesi (DP) equation are cast in the same peakon family, they possess the second- and third-order Lax operat…

math-ph2023

The defocusing NLS equation with nonzero background: Painlevé asymptotics in two transition regions

Zhaoyu Wang, Engui Fan

In this paper, we address the Painlevé aymptotics in the transition region to the Cauchy problem of the defocusing Schrdi…

math.AP2023

Existence of global solutions for the nonlocal derivation nonlinear Schrödinger equation by the inverse scattering transform method

Yuan Li, Xinhan Liu, Engui Fan

We address the existence of global solutions to the initial value problem for the integrable nonlocal derivative nonlinear Schrödinger equation in weighted Sobolev space $H^{2}(\m…

nlin.SI2013

Reality problems for the Algebro-Geometric Solutions of Fokas-Lenell hierarchy

Peng Zhao, Engui Fan

In a previous study, we obtained the algebro-geometric solutions and -dark solitons of Forkas-Lenells (FL) hierarchy using algebro-geometric method. In this paper, we construct…

math.AP2023

Existence of global solutions to the nonlocal mKdV equation on the line

Anran Liu, Engui Fan

In this paper, we address the existence of global solutions to the Cauchy problem for the integrable nonlocal modified Korteweg-de vries (nonlocal mKdV) equation with the initial d…

math.AP2026

Local and global well-posedness for the nonlinear Schrödinger equation with nonhomogeneous boundary conditions

Engui Fan, Yuan Li, Xinhan Liu

In this paper, we study the initial-boundary value problem for the nonlinear Schrödinger equation in \begin{equation*} i\partial_{t}u+Δu+λ|u|^pu=0, \qquad (…

math.AP2026

Painleve XXXIV asymptotics for the defocusing mKdV equation with step-like initial data in transition regions

Engui Fan, Zhaoyu Wang, Yidan Zhang

In this paper, we consider the Cauchy problem for the defocusing modified Korteweg-de Vries (mKdV) equation with a step-like initial data. Based on the Riemann-Hilbert problem asso…

math.AP2024

The Cauchy problem for the Degasperis-Procesi Equation: Painlevé Asymptotics in Transition Zones

Zhaoyu Wang, Xuan Zhou, Engui Fan

The Degasperis-Procesi (DP) equation \begin{align} &u_t-u_{txx}+3κu_x+4uu_x=3u_x u_{xx}+uu_{xxx}, \nonumber \end{align} serving as an asymptotic approximation for the unidirection…

math-ph2022

Long-time asymptotic behavior for the Novikov equation in solitonic regions of space time

Yiling Yang, Engui Fan

In this paper, we study the long time asymptotic behavior for the Cauchy problem of the Novikov equation with matrix spectral problem \begin{align} &u_{t}-u_{txx}+4 u_{…

math.AP2022

The complex mKdV equation with step-like initial data: Large time asymptotic analysis

Zhaoyu Wang, Kai Xu, Engui Fan

In this paper, we study large-time asymptotics for the complex modified Korteveg-de Vries equation \begin{equation} u_t + \frac{1}{2}u_{xxx}+3|u|^2 u_x=0, \end{equation} with the s…

nlin.SI2019

Long time asymptotics behavior of the focusing nonlinear Kundu-Eckhaus equation

Ruihong Ma, Engui Fan

We study the Cauchy problem for the focusing nonlinear Kundu-Eckhaus equation and construct long time asymptotic expansion of its solution in fixed space-time cone with $C(x_1,x_2,…

nlin.SI2017

Initial-boundary value problem for the two-component Gerdjikov-Ivanov equation on the interval

Qiaozhen Zhu, Jian Xu, Engui Fan

In this paper, we apply Fokas unified method to study initial-boundary value problems for the two-component Gerdjikov-Ivanov equation formulated on the finite interval with $3 \tim…

math-ph2026

Painlevé XXXIV Asymptotics for the Focusing mKdV Equation with Finite-Genus Background and Discrete Spectrum

Ruihong Ma, Engui Fan

We investigate the Cauchy problem for the focusing modified Korteweg--de Vries (mKdV) equation with finite-genus algebro-geometric quasi-periodic initial data. By applying the nonl…

nlin.SI2017

Hankel determinants for a perturbed Laguerre weight and Painleve V equation

Min Chen, Yang Chen, Engui Fan

In this paper, we study Hankel determinants generated from a perturbed Laguerre weight function, Under the double scaling scheme, we give the uniform asymptotic approximations of H…

nlin.SI2010

Explicit quasi-periodic wave solutions and asymptotic analysis to the supersymmetric Ito's equation

Engui Fan, Y. C. Hon

Based on a Riemann theta function and the super-Hirota bilinear form, we propose a key formula for explicitly constructing quasi-periodic wave solutions of the supersymmetric Ito's…

math.AP2023

Long time asymptotic behavior for the nonlocal nonlinear Schrödinger equation with weighted Sobolev initial data

Gaozhan Li, Yiling Yang, Engui Fan

In this paper, we extend steepest descent method to study the Cauchy problem for the nonlocal nonlinear Schrödinger (NNLS) equation with weighted Sobolev initi…

nlin.SI2012

The algebro-geometric solutions for Hunter-Saxton hierarchy

Yu Hou, Engui Fan, Peng Zhao

This paper is dedicated to provide theta function representation of algebro-geometric solutions and related crucial quantities for the Hunter-Saxton (HS) hierarchy through studying…

math-ph2022

Painleve-type asymptotics for the defocusing Hirota equation in transition region

Weikang Xun, Luman Ju, Engui Fan

We consider the Cauchy problem for the classical Hirota equation on the line with decaying initial data. Based on the spectral analysis of the Lax pair of the Hirota equation, we f…

math.AP2021

Long time and Painleve-type asymptotics for the Sasa-Satsuma equation in solitonic space time regions

Weikang Xun, Engui Fan

The Sasa-Satsuma equation with Lax representation is one of the integrable extensions of the nonlinear Schrödinger equation. In this paper, we consider the Cauchy pr…

math-ph2025

Painlevé transcendents in the defocusing mKdV equation with non-zero boundary conditions

Zhaoyu Wang, Taiyang Xu, Engui Fan

We consider the Cauchy problem for the defocusing modified Korteweg-de Vries (mKdV) equation with non-zero boundary conditions \begin{align} &q_t(x,t)-6q^2(x,t)q_{x}(x,t)+q_{xxx}(x…

nlin.SI2019

Inverse scattering transformation for the Fokas-Lenells equation with nonzero boundary conditions

Yi Zhao, Engui Fan

In this article, we focus on the inverse scattering transformation for the Fokas-Lenells (FL) equation with nonzero boundary conditions via the Riemann-Hilbert (RH) approach. Based…

nlin.SI2015

The unified transform method for the Sasa-Satsuma equation on the interval

Jian Xu, Qiaozhen Zhu, Engui Fan

We present a Riemann-Hilbert problem formalism for the initial-boundary value problem for the Sasa-Satsuma(SS) equation on the finite interval. Assume that the solution existes, we…

nlin.SI2019

Long-time asyptotics behavior for the integrable modified Camassa-Holm equation with cubic nonlinearity

Jian Xu, Engui Fan

In this paper, we investigate the long-time asymptotic behavior of the solution to the initial value problem for the modified Camassa-Holm (mCH) equation with cubic nonlinearity. T…

math-ph2015

Large n-limit for Random matrices with External Source with 3 eigenvalues

Jian Xu, Engui Fan, Yang Chen

In this paper, we analyze the large n-limit for random matrix with external source with three distinct eigenvalues. And we confine ourselves in the Hermite case and the three disti…

math-ph2025

Soliton resolution, asymptotic stability and Painlevé transcendents in the combined Wadati-Konno-Ichikawa and short-pulse equation

Yidan Zhang, Engui Fan

In this paper, we develop a Riemann-Hilbert (RH) approach to the Cauchy problem for the combined Wadati-Konno-Ichikawa and short-pulse (WKI-SP) equation. The solution of the Cauchy…

nlin.SI2014

Algebro-geometric solutions for the two-component Camassa-Holm Dym hierarchy

Yu Hou, Engui Fan

This paper is dedicated to provide theta function representations of algebro-geometric solutions and related crucial quantities for the two-component Camassa-Holm Dym (CHD2) hierar…

math.AP2023

The Cauchy problem of the Camassa-Holm equation in a weighted Sobolev space: Long-time and Painlevé asymptotics

Kai Xu, Yiling Yang, Engui Fan

Based on the -generalization of the Deift-Zhou steepest descent method, we extend the long-time and Painlevé asymptotics for the Camassa-Holm (CH) equation to t…

math-ph2017

Critical edge behavior in the perturbed Laguerre ensemble and the Painleve V transcendent

Min Chen, Yang Chen, Engui Fan

In this paper, we consider the perturbed Laguerre unitary ensemble described by the weight function of with The…

nlin.SI2013

The unified method for the three-wave equation on the half-line

Jian Xu, Engui Fan

We present a Riemann-Hilbert problem formalism for the initial-boundary value problem for the three-wave equation: \[p_{ij,t}-\frac{b_i-b_j}{a_i-a_j}p_{ij,x}+\sum_k(\frac{b_k-b_j}{…

math-ph2026

A dense focusing Ablowitz-Ladik soliton gas and its asymptotics

Meisen Chen, Engui Fan, Zhaoyu Wang +2

In this paper, we propose a soliton gas solution for the focusing Ablowitz-Ladik system. This solution is defined as the large N limit of the N-soliton solution, and arises from a…

nlin.SI2019

The Riemann-Hilbert approach to focusing Kundu-Eckhaus equation with nonzero boundary conditions

Lili Wen, Engui Fan

In this article, we focus on investigating the focusing Kundu-Eckhaus equation with nonzero boundary condition. A appropriate two-sheeted Riemann surface is introduced to map the s…

nlin.SI2018

Long-time asymptotics for the Nonlocal mKdV equation

Fengjing He, Engui Fan, Jian Xu

In this paper, we study the Cauchy problem with decaying initial data for the nonlocal modified Korteweg-de Vries equation (nonlocal mKdV) \[q_t(x,t)+q_{xxx}(x,t)-6q(x,t)q(-x,-t)q_…

nlin.SI2015

Initial-boundary value problem for integrable nonlinear evolution equations with Lax pairs on the interval

Jian Xu, Engui Fan

We present an approach for analyzing initial-boundary value problems which is formulated on the finite interval (, where is a positive constant) for integrable equ…

math.AP2021

On asymptotic approximation of the modified Camassa-Holm equation in different space-time solitonic regions

Yiling Yang, Engui Fan

In this paper, we study the long time asymptotic behavior for the initial value problem of the modified Camassa-Holm (mCH) equation in the solitonic region \begin{align} &m_{t}+\le…

math.AP2023

The asymptotic stability of solitons in the focusing Hirota equation on the line

Ruihong Ma, Engui Fan

In this paper, the -steepest descent method and Bäcklund transformation are used to study the asymptotic stability of solitons to the Cauchy problem of focusing…

math.AP2023

he Cauchy problem for the Novikov equation under a nonzero background: Painlevé asymptotics in a transition zone

Zhaoyu Wang, Xuan Zhou, Engui Fan

In this paper, we investigate the Painlevé asymptotics in a transition zone for the solutions to the Cauchy problem of the Novikov equation under a nonzero background \begin{align…

nlin.SI2010

A Riemann theta function formula with its application to double periodic wave solutions of nonlinear equations

Engui Fan, Kwok Wing Chow

Based on a Riemann theta function and Hirota's bilinear form, a lucid and straightforward way is presented to explicitly construct double periodic wave solutions for both nonlinear…

math-ph2026

Painlevé Asymptotics of the Focusing Nonlinear Schrödinger Equation with a Finite-Genus Algebro-Geometric Background

Ruihong ma, Engui Fan

We investigate the Cauchy problem for the focusing nonlinear Schrödinger (NLS) equation \begin{equation} iq_t(x,t)+q_{xx}(x,t)+2|q(x,t)|^2q(x,t)=0,\quad x\in\mathbb{R},\quad t\ge0…

math.AP2026

Painlevé XXXIV asymptotics for the defocusing nonlinear Schrödinger equation with a finite-genus algebro-geometric background

Engui Fan, Gaozhan Li, Yiling Yang +1

In this paper, we consider the Cauchy problem for the defocusing nonlinear Schrdinger equation with a finite genus algebro-geometric background. Long-time asymptot…

math.AP2022

The defocusing NLS equation with nonzero background: Large-time asymptotics in the solitonless region

Zhaoyu Wang, Engui Fan

We consider the Cauchy problem for the defocusing Schrdinger (NLS) equation with a nonzero background $$\begin{align} &iq_t+q_{xx}-2(|q|^2-1)q=0, \nonumber\\ &q(x,…

nlin.SI2019

Long-time asymptotic behavior of the modified Schrödinger equation via Dbar-steepest descent method

Yiling Yang, Engui Fan

In this paper, we consider the Cauchy problem for the modified NLS equation. Using nonlinear steepest descent method and combining the Dbar-analysis, we show that inside any fixed…

math.AP2023

On the Cauchy problem of defocusing mKdV equation with finite density initial data: long time asymptotics in soliton-less regions

Taiyang Xu, Zechuan Zhang, Engui Fan

We investigate the long-time asymptotics for the solutions to the Cauchy problem of defocusing modified Kortweg-de Vries (mKdV) equation with finite density initial data. The prese…

nlin.SI2020

Soliton Resolution for the Short-pluse Equation

Yiling Yang, Engui Fan

In this paper, we study the Cauchy problem for the focusing nonlinear short-pluse equation by using steepest descent method. \begin{align} &u_{xt}=u+\frac{1}{6}…

math-ph2025

Riemann-Hilbert approach to the Algebro-Geometric solution of the modified Camassa-Holm equation with linear dispersion term

Engui Fan, Gaozhan Li, Yiling Yang

This paper aims at providing an exact algebro-geometric solution of the modified Camassa-Holm (mCH) equation derived from hyperelliptic curves in genus. To achieve this…