Minimal surfaces in random environment
Barbara Dembin, Dor Elboim, Daniel Hadas, Ron Peled
TL;DR
We study minimal surfaces in a random environment (MSRE) by minimizing an energy that blends elastic interactions with a random environment term, focusing on the harmonic (no-overhang) case with independent disorder. A central main identity controls energy changes under joint shifts of the surface and disorder, enabling sharp probabilistic and multiscale arguments. The paper establishes a rigorous scaling relation chi = 2 xi + d - 2 between ground energy fluctuations chi and transversal height fluctuations xi, proving delocalization in dimensions d <= 4 and localization in d >= 5, with power-law height fluctuations for d <= 3 and sub-power-law behavior at d = 4. The results connect with physical predictions, discuss disorder universality, and outline open problems and extensions including periodic disorder, scaling limits, and more general elastic operators.
Abstract
A minimal surface in a random environment (MSRE) is a surface which minimizes the sum of its elastic energy and its environment potential energy, subject to prescribed boundary conditions. Apart from their intrinsic interest, such surfaces are further motivated by connections with disordered spin systems and first-passage percolation models. We wish to study the geometry of $d$-dimensional minimal surfaces in a $(d+n)$-dimensional random environment. Specializing to a model that we term harmonic MSRE, in an ``independent'' random environment, we rigorously establish bounds on the geometric and energetic fluctuations of the minimal surface, as well as versions of the scaling relation $χ=2ξ+d-2$ that ties together these two types of fluctuations. In particular, we prove, for all values of $n$, that the surfaces are delocalized in dimensions $d\le 4$ and localized in dimensions $d\ge 5$. Moreover, the surface delocalizes with power-law fluctuations when $d\le 3$ and sub-power-law fluctuations when $d=4$. Our localization results apply also to harmonic minimal surfaces in a periodic random environment.
