English

Khasminskii--Whitham averaging for randomly perturbed KdV equation

Analysis of PDEs 2007-10-23 v1 Mathematical Physics math.MP

Abstract

We consider the damped-driven KdV equation u˙νuxx+uxxx6uux=νη(t,x),xS1,udxηdx0, \dot u-\nu{u_{xx}}+u_{xxx}-6uu_x=\sqrt\nu \eta(t,x), x\in S^1, \int u dx\equiv \int\eta dx\equiv0, where 0<ν10<\nu\le1 and the random process η\eta is smooth in xx and white in tt. For any periodic function u(x)u(x) let I=(I1,I2,...) I=(I_1,I_2,...) be the vector, formed by the KdV integrals of motion, calculated for the potential u(x)u(x). We prove that if u(t,x)u(t,x) is a solution of the equation above, then for 0tν10\le t\lesssim\nu^{-1} and ν0\nu\to0 the vector I(t)=(I1(u(t,)),I2(u(t,)),...) I(t)=(I_1(u(t,\cdot)),I_2(u(t,\cdot)),...) satisfies the (Whitham) averaged equation.

Cite

@article{arxiv.0710.3869,
  title  = {Khasminskii--Whitham averaging for randomly perturbed KdV equation},
  author = {Sergei B. Kuksin and Andrey L. Piatnitski},
  journal= {arXiv preprint arXiv:0710.3869},
  year   = {2007}
}
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