English

Generalized selection problem with L\'evy noise

Probability 2020-04-14 v1

Abstract

Let A±>0A_\pm>0, β(0,1)\beta\in(0,1), and let Z(α)Z^{(\alpha)} be a strictly α\alpha-stable L\'evy process with the jump measure ν(dz)=(C+I(0,)(z)+CI(,0)(z))z1αdz\nu(\mathrm{d} z)=(C_+\mathbb{I}_{(0,\infty)}(z)+ C_-\mathbb{I}_{(-\infty,0)}(z))|z|^{-1-\alpha}\,\mathrm{d} z, α(1,2)\alpha\in (1,2), C±0C_\pm\geq 0, C++C>0C_++C_->0. The selection problem for the model stochastic differential equation dXˉε=(A+I[0,)(Xˉε)AI(,0)(Xˉε))Xˉεβdt+εdZ(α)\mathrm{d} \bar X^\varepsilon=(A_+\mathbb{I}_{[0,\infty)}(\bar X^\varepsilon) - A_-\mathbb{I}_{(-\infty,0)}(\bar X^\varepsilon))|\bar X^\varepsilon|^\beta \,\mathrm{d} t +\varepsilon \mathrm{d} Z^{(\alpha)} states that in the small noise limit ε0\varepsilon\to 0, solutions Xˉε\bar X^\varepsilon converge weakly to the maximal or minimal solutions of the limiting non-Lipschitzian ordinary differential equation dxˉ=(A+I[0,)(xˉ)AI(,0)(xˉ))xˉβdt\mathrm{d} \bar x=(A_+\mathbb{I}_{[0,\infty)}(\bar x)- A_-\mathbb{I}_{(\infty,0)}(\bar x))|\bar x|^\beta \,\mathrm{d} t with probabilities pˉ±=pˉ±(α,C+/C,β,A+/A)\bar p_\pm=\bar p_\pm(\alpha,C_+/C_-,\beta, A_+/A_-), see [Pilipenko and Proske, Stat. Probab. Lett., 132:62-73, 2018]. In this paper we solve the generalized selection problem for the stochastic differential equation dXε=a(Xε)dt+εb(Xε)dZ\mathrm{d} X^\varepsilon=a(X^\varepsilon)\,\mathrm{d} t+\varepsilon b(X^\varepsilon)\,\mathrm{d} Z whose dynamics in the vicinity of the origin in certain sense reminds of dynamics of the model equation. In particular we show that solutions XεX^\varepsilon also converge to the maximal or minimal solutions of the limiting irregular ordinary differential equation dx=a(x)dt\mathrm{d} x=a(x) \,\mathrm{d} t with the same model selection probabilities pˉ±\bar p_\pm. This means that for a large class of irregular stochastic differential equations, the selection dynamics is completely determined by four local parameters of the drift and the jump measure.

Keywords

Cite

@article{arxiv.2004.05421,
  title  = {Generalized selection problem with L\'evy noise},
  author = {Ilya Pavlyukevich and Andrey Pilipenko},
  journal= {arXiv preprint arXiv:2004.05421},
  year   = {2020}
}

Comments

17 pages

R2 v1 2026-06-23T14:48:03.268Z