# SCALAR: an AMR code to simulate axion-like dark matter models

## TL;DR

SCALAR is a new adaptive mesh code based on RAMSES that accurately simulates axion-like dark matter models by solving the Schr"odinger-Poisson equations, enabling detailed studies of fuzzy dark matter.

## Contribution

It introduces a novel Schr"odinger equation solver integrated with RAMSES for simulating axion-like dark matter models with adaptive refinement.

## Key findings

- Demonstrates accurate numerical implementation through tests
- Enables simulation of non-linear Schr"odinger equations with external potentials
- Provides a versatile tool for dark matter research

## Abstract

We present a new code, SCALAR, based on the high-resolution hydrodynamics and N-body code RAMSES, to solve the Schr\"odinger equation on adaptive refined meshes. The code is intended to be used to simulate axion or fuzzy dark matter models where the evolution of the dark matter component is determined by a coupled Schr\"odinger-Poisson equation, but it can also be used as a standalone solver for both linear and non-linear Schr\"odinger equations with any given external potential. This paper describes the numerical implementation of our solver and presents tests to demonstrate how accurately it operates.