# Averaging Principle and Shape Theorem for a Growth Model with Memory

## TL;DR

This paper introduces a unified approach to analyze a class of self-interacting random growth models in Euclidean space, establishing an averaging principle and shape theorem that describe their large-scale behavior.

## Contribution

It develops a general averaging principle and shape theorem for growth models with memory, linking the limiting shape to the invariant measure of an associated Markov chain.

## Key findings

- Proves an averaging principle for self-interacting growth models.
- Establishes a shape theorem describing the asymptotic growth shape.
- Shows the limiting shape can be computed via an invariant measure.

## Abstract

We present a general approach to study a class of random growth models in $n$-dimensional Euclidean space. These models are designed to capture basic growth features which are expected to manifest at the mesoscopic level for several classical self-interacting processes originally defined at the microscopic scale. It includes once-reinforced random walk with strong reinforcement, origin-excited random walk, and few others, for which the set of visited vertices is expected to form a "limiting shape". We prove an averaging principle that leads to such shape theorem. The limiting shape can be computed in terms of the invariant measure of an associated Markov chain.