Jaxions is a grid-based massively parallel code to study the Axion field evolution before, around and after the QCD phase transition.

To compile the code and run a typical simulation you will need the following libraries:

• Working C/C++ compilers (for GNU version 4.x or later)
• CMake tools (CMake)
• GNU Scientific Library (GSL)
• Fastest Fourier Transform in the West (FFTW3)
• Hierarchical Data Format (HDF5)
• Message Passing Interface (MPI), version 3.0 or higher. Examples are Intel-MPI, OpenMPI, MPICH

To install the code clone the repository

git clone https://github.com/veintemillas/jaxions.git; cd jaxions

Then you can use cmake to build the code

mkdir build; cd build
cmake -S ../jaxions -B .
cmake --build build -j<n_procs>

The deafult branch is 'redondo', this might change in the future.

A documentation is under development. For reference on the physics implemented, please refer to the main paper:

• A. Vaquero, J. Redondo, J. Stadler, Early seeds of axion miniclusters, 1809.09241