DarkNewt

Tolman–Oppenheimer–Volkoff modelling of dark-matter admixed neutron stars

Overview

DarkNewt is a Python package for modelling compact stars containing nuclear matter and dark matter using the Tolman–Oppenheimer–Volkoff (TOV) equations.

The package can be used to calculate:

• Mass–radius relations of neutron stars
• Pure nuclear-matter neutron-star sequences
• Two-fluid nuclear-matter + dark-matter configurations
• Individual nuclear-matter and dark-matter masses
• Individual fluid radii
• Total stellar mass and radius
• Dimensionless tidal deformability
• Mass–tidal-deformability relations
• Configurations at fixed dark-matter mass fraction

The package is designed primarily for research and exploratory work in neutron-star and gravitational-wave physics.

Installation

From PyPI

conda create -n darknewt-env python=3.11 -y
conda activate darknewt-env
python -m pip install darknewt

Install from source

Quickest way is this:

conda create -n darknewt-env python=3.11 -y
conda activate darknewt-env
python -m pip install git+https://gitlab.com/samanwaya-mukherjee/darknewt.git

Features

Equation of state

darknewt provides a common EOS interface supporting both tabulated and analytic equations of state.

Built-in nuclear-matter EOS tables include, among others:

• AP1
• AP3
• AP4 / APR4
• MPA1
• MS1
• H1
• H4
• SLy

Several Bose–Einstein condensate (BEC) dark-matter EOS tables are also included.

User-supplied EOS tables can be loaded from a file containing:

density [g/cm^3]    pressure [dyn/cm^2]

Project structure

darknewt/
├── assets/
│   └── darknewt_logo.png
├── darknewt/
│   ├── __init__.py
│   ├── constants.py
│   ├── love.py
│   ├── solver.py
│   ├── tov.py
│   ├── utils.py
│   └── eos/
│       ├── __init__.py
│       ├── base.py
│       ├── models.py
│       └── eos_data/
│           ├── AP1.dat
│           ├── ...
├── examples/
│   └── test.py
├── README.md
├── LICENSE
├── CHANGELOG.md
└── pyproject.toml