# Rate of Convergence of General Phase Field Equations towards their Homogenized Limit

## TL;DR

This paper derives the first error estimates for fourth order, nonlinear phase-field equations in heterogeneous porous media, revealing a convergence rate of approximately     in terms of heterogeneity scale.

## Contribution

It provides the first derivation of error estimates for fourth order, homogenized, nonlinear phase-field equations in strongly heterogeneous materials.

## Key findings

- Error estimate with convergence rate     for the homogenized solution
- First analysis of fourth order phase-field equations in heterogeneous media
- Motivates new approaches in modeling and computation of interfacial phenomena

## Abstract

Over the last few decades, phase-field equations have found increasing applicability in a wide range of mathematical-scientific fields (e.g. geometric PDEs and mean curvature flow, materials science for the study of phase transitions) but also engineering ones (e.g. as a computational tool in chemical engineering for interfacial flow studies). Here, we focus on phase-field equations in strongly heterogeneous materials with perforations such as porous media. To the best of our knowledge, we provide the first derivation of error estimates for fourth order, homogenized, and nonlinear evolution equations. Our fourth order problem induces a slightly lower convergence rate, i.e., $\epsilon^{1/4}$, where $\epsilon$ denotes the material's specific heterogeneity, than established for second-order elliptic problems (e.g. \cite{Zhikov2006}) for the error between the effective macroscopic solution of the (new) upscaled formulation and the solution of the microscopic phase field problem. We hope that our study will motivate new modelling, analytic, and computational perspectives for interfacial transport and phase transformations in strongly heterogeneous environments.