# COLA with scale-dependent growth: applications to screened modified gravity models

## TL;DR

This paper introduces a parallelized COLA-based simulation code capable of modeling structure formation in cosmologies with scale-dependent growth, including screening mechanisms for modified gravity theories, validated against full simulations.

## Contribution

The paper presents a new efficient simulation code that incorporates scale-dependent growth and screening mechanisms for modified gravity models, enabling faster and accurate structure formation studies.

## Key findings

- Good agreement with full simulations for $f(R)$ and nDGP models
- Effective modeling of screening mechanisms in modified gravity
- Accurate boost-factor predictions with few COLA steps

## Abstract

We present a general parallelized and easy-to-use code to perform numerical simulations of structure formation using the COLA (COmoving Lagrangian Acceleration) method for cosmological models that exhibit scale-dependent growth at the level of first and second order Lagrangian perturbation theory. For modified gravity theories we also include screening using a fast approximate method that covers all the main examples of screening mechanisms in the literature. We test the code by comparing it to full simulations of two popular modified gravity models, namely $f(R)$ gravity and nDGP, and find good agreement in the modified gravity boost-factors relative to $\Lambda$CDM even when using a fairly small number of COLA time steps.