Singular diffusion limit of a tagged particle in zero range processes with Sinai-type random environment

Abstract

We derive a singular diffusion limit for the position of a tagged particle in zero range interacting particle processes on a one dimensional torus with a Sinai-type random environment via two steps. In the first step, a regularization is introduced by averaging the random environment over an $\varepsilon N$-neighborhood. With respect to such an environment, the microscopic drift of the tagged particle is in form $\frac{1}{N}W_\varepsilon'$, where $W_\varepsilon'$ is a regularized White noise. Scaling diffusively, we find the nonequilibrium limit of the tagged particle $x^\varepsilon_t$ is the unique weak solution of $d x_t^{\varepsilon} = 2\frac{Φ(ρ^{\varepsilon}(t, x_t^{\varepsilon}))}{ρ^{\varepsilon}(t, x_t^\varepsilon)} \,W_{\varepsilon}'(x_t^\varepsilon) + \sqrt{\frac{Φ(ρ^{\varepsilon}(t, x_t^\varepsilon))}{ρ^{\varepsilon}(t, x_t^\varepsilon)}} \,dB_t$, in terms of the hydrodynamic mass density $ρ^\varepsilon$ recently identified and homogenized interaction rate $Φ$. In the second step, we show that $x^\varepsilon$, as $\varepsilon$ vanishes, converges in law to the diffusion $x^0$ described informally by $d x_t^0 = 2\frac{Φ(ρ^{0}(t, x_t^{0}))}{ρ^{0}(t, x_t^0)} \,W'(x_t^0) + \sqrt{\frac{Φ(ρ^{0}(t, x_t^0))}{ρ^{0}(t, x_t^0)}} \,dB_t$, where $W'$ is a spatial White noise and $ρ^0$ is the para-controlled limit of $ρ^\varepsilon$ also recently identified, solving the singular PDE $ \partial_t ρ^0 = \frac{1}{2}ΔΦ(ρ^0) - 2\nabla \big(W' Φ(ρ^0)\big)$.

Theorems & Definitions (48)

• Lemma 2.1
• Proposition 2.2
• Proposition 2.4
• proof
• Remark 2.5
• Lemma 2.6
• proof
• Theorem 2.7
• Definition 2.8
• Remark 2.9