Discrete-to-continuum limits of optimal transport with linear growth on periodic graphs
Lorenzo Portinale, Filippo Quattrocchi
TL;DR
This work establishes discrete-to-continuum Gamma-convergence for dynamical optimal transport on $\mathbb{Z}^d$-periodic graphs with energy densities of linear growth or flow-based form. It extends previous superlinear-growth results to linear-growth settings, enabling the homogenization of boundary-value transport problems and revealing that the limit energy is governed by a cell-formula $f_\mathrm{hom}$ whose geometry is dictated by the underlying graph. The key contributions include a limsup and liminf analysis, separation of linear-growth and flow-based cases, and a detailed cell-problem analysis with explicit examples showing how $f_\mathrm{hom}$ can yield $W_1$-type limits and crystalline norms. The results have implications for understanding scaling limits of $1$-Wasserstein transport, and they illuminate how graph geometry shapes the homogenized cost, supported by embedded-graph examples and visualizations.
Abstract
We prove discrete-to-continuum convergence for dynamical optimal transport on $\mathbb{Z}^d$-periodic graphs with energy density having linear growth at infinity. This result provides an answer to a problem left open by Gladbach, Kopfer, Maas, and Portinale (Calc Var Partial Differential Equations 62(5), 2023), where the convergence behaviour of discrete boundary-value dynamical transport problems is proved under the stronger assumption of superlinear growth. Our result extends the known literature to some important classes of examples, such as scaling limits of 1-Wasserstein transport problems. Similarly to what happens in the quadratic case, the geometry of the graph plays a crucial role in the structure of the limit cost function, as we discuss in the final part of this work, which includes some visual representations.
