English

Scaling limit of the complex mobility matrix for the random conductance model on $\mathbb{T}^d_N$

Probability 2025-12-18 v1 Mathematical Physics math.MP

Abstract

We consider a continuous-time random walk on the dd-dimensional torus TNd=Zd/NZd\mathbb{T}^d_{N}=\mathbb{Z}^d/N \mathbb{Z}^d, possibly with long-range, but finite, jumps. The law of the jumps is regulated by a random environment ξ\xi yielding a stationary and ergodic field of random conductances. The complex mobility matrix σNξ(ω)\sigma_N^\xi(\omega) measures the linear response of the random walk to a cos(ωt)\cos(\omega t)-type oscillating external field. By investigating the homogenization properties of the medium, and assuming in addition that the conductances have finite second moment, we show that, for almost every realization of the environment ξ\xi, the complex mobility matrix σNξ(ω)\sigma_N^\xi(\omega) converges as N+N\to+\infty to a deterministic limiting matrix σ(ω)\sigma(\omega) and provide different characterizations of σ(ω)\sigma(\omega).

Keywords

Cite

@article{arxiv.2512.15506,
  title  = {Scaling limit of the complex mobility matrix for the random conductance model on $\mathbb{T}^d_N$},
  author = {Alessandra Faggionato and Michele Salvi},
  journal= {arXiv preprint arXiv:2512.15506},
  year   = {2025}
}

Comments

35 pages, 3 figures