论文标题
非局部MKDV方程的长期渐近行为在时空孤子区域-II中
Long time asymptotic behavior for the nonlocal mKdV equation in space-time solitonic regions-II
论文作者
论文摘要
我们研究了cauchy问题的长时间渐近行为,即在孤子区域中具有非零初始数据的可集成的实际非局部MKDV方程\ Begin \ begin {align*}&q_t(x,x,x,t)-6σq(x,x,x,x,x,t)q(-x,-t,-t) &q(x,0)= q_ {0}(x),\\ lim_ {x \ to \ pm \ pm \ infty} q_ {0}(x)= q _ {\ pm},\ end \ end {align {align {align {align {align*} $ | _ | q _ {\ q _ {\ pm} $ = 1 $和$ q | = 1 $和$ q _} $σδ= -1 $。在上一篇文章中,我们在孤子区域中的非局部MKDV方程$ -6 <ξ<6 $中获得了很长时间的渐近学,而$ξ= \ frac {x} {t} $。在本文中,我们计算了其他孤子区域的解决方案$ q(x,t)$的渐近扩展,$ξ<-6 $和$ξ> 6 $。基于Riemann-Hilbert问题的问题,进一步使用了$ \ bar {\ partial} $陡峭的下降方法,我们在两个以上的时空孤子区域中得出了解决方案$ q(x,t)$的不同长期渐近扩展。在区域$ξ<-6 $中,相位函数$θ(z)$在$ \ mathbb {r} $上具有四个固定相点。相应地,$ q(x,t)$可以用$ \ MATHCAL {n}(λ)$ - soliton在离散频谱上,连续频谱上的领先订单术语和残留误差术语来表征,该术语受函数$ {\ rm im}ν(emem}ν(eζ_i)$的影响。在区域$ξ> 6 $中,相位函数$θ(z)$在$ i \ mathbb {r} $上具有四个固定相位点,可以用$ \ mathcal {n}(N}(λ)$ - soliton,带有多样的残留错误顺序$ \ nathcal $ \ nathcal $ \ \ m varycal $ \ \ natcal {o}(o}(o}(o}),
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_t(x,t)-6σq(x,t)q(-x,-t)q_{x}(x,t)+q_{xxx}(x,t)=0, &q(x,0)=q_{0}(x),\ \ \lim_{x\to \pm\infty} q_{0}(x)=q_{\pm}, \end{align*} where $|q_{\pm}|=1$ and $q_{+}=δq_{-}$, $σδ=-1$. In our previous article, we have obtained long time asymptotics for the nonlocal mKdV equation in the solitonic region $-6<ξ<6$ with $ξ=\frac{x}{t}$. In this paper, we calculate the asymptotic expansion of the solution $q(x,t)$ for other solitonic regions $ξ<-6$ and $ξ>6$. Based on the Riemann-Hilbert problem of the the Cauchy problem, further using the $\bar{\partial}$ steepest descent method, we derive different long time asymptotic expansions of the solution $q(x,t)$ in above two different space-time solitonic regions. In the region $ξ<-6$, phase function $θ(z)$ has four stationary phase points on the $\mathbb{R}$. Correspondingly, $q(x,t)$ can be characterized with an $\mathcal{N}(Λ)$-soliton on discrete spectrum, the leading order term on continuous spectrum and an residual error term, which are affected by a function ${\rm Im}ν(ζ_i)$. In the region $ξ>6$, phase function $θ(z)$ has four stationary phase points on $i\mathbb{R}$, the corresponding asymptotic approximations can be characterized with an $\mathcal{N}(Λ)$-soliton with diverse residual error order $\mathcal{O}(t^{-1})$.