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

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.