## Project List

Current **Mathematica** projects in the Toolkit include:

- SpinWeightedSpheroidalHarmonics: Tools for computing spin-weighted spheroidal harmonics and their associated eigenvalues.
- KerrGeodesics: Tools for computing bound timelike geodesics about a Kerr black hole.
- Teukolsky: A set of functions for computing solutions to the Teukolsky equation for perturbations of the spacetime of a Kerr black hole.
- QuasiNormalModes: Tools for computing quasinormal modes in Schwarzschild and Kerr spacetime
- GeneralRelativityTensors: Provides a set of functions for performing coordinate-based tensor calculations with a focus on general relativity and black holes in particular.
- ReggeWheeler: A set of functions for computing solutions to the Regge-Wheeler equation for perturbations of the spacetime of a Schwarzschild black hole.
- PerturbationEquations: A set of tools for working with the spherical-harmonic decompositions of the first- and second-order Einstein equations and Teukolsky equations in Schwarzschild spacetime.

Current **C/C++** projects in the Toolkit include:

- Fast Self-forced Inspirals: Code to compute self-force inspirals rapidly using the near-identity transformed (NITâ€™d) equations of motion.
- EMRI Kludge Suite: A suite of software for computing kludge waveforms for generic extreme mass-ratio inspirals into a Kerr black hole.
- Gremlin: Code to solve the Teukolsky equation with a point-particle source
- h1Lorenz: Code to compute the first-order metric perturbation in the Lorenz gauge
- SecondOrderRicci: Computes the modes of the second-order Ricci tensor

Current **Python** and **SageMath** projects in the Toolkit include:

- kerrgeodesic_gw: SageMath code to compute the gravitational waves from a particle on a circular orbit about a Kerr black hole. Also included is code to compute spin weighted spheroidal harmonics.
- qnm: Python implementation of Cook-Zalutskiy spectral approach to computing Kerr QNM frequencies. Spherical-spheroidal decomposition coefficients are computed for free with frequencies and separation constants. Includes a precomputed cache of low-lying multipoles and overtones.
- BHPTNRSurrogate: Python code to evaluate gravitational waveform surrogate models trained on waveform data generated by point-particle black hole perturbation theory and calibrated to numerical relativity waveforms.
- FastEMRIWaveforms: Python code that creates fast and accurate EMRI waveforms on both CPUs and GPUs.
- KerrGeoPy: Python code for working with timelike geodesics in the Kerr spacetime.

Current **Fortran** projects in the Toolkit include:

- Self-Force-1D: SelfForce-1D is a code infrastructure for simulating Extreme Mass Ratio Inspirals using the effective source approach to the self-force problem.

A range of further tools are being developed and will be added as the project expands. There is also a **repository of results** associated with the Toolkit. Large datasets can be found in our BHPToolkit Zenodo community. Smaller datasets and packages for manipulating the data include:

- PostNewtonian-SelfForce: Results for various quantities to high post-Newtonian order and linear-order in the mass ratio. This repository includes a Mathematica package for easy loading and manipulation of the PN series.
- RegularizationParameters: Regularization parameters to compute the regular field at the particle.
- Circular Orbit Self-force Data: Numerical data for fluxes and self-force quantities for circular orbits

We also have **example code** which demonstrates how to use various pieces of the Toolkit:

- Mathematica Toolkit Examples: Examples using the Mathematica modules of the Toolkit

## Citation Guideline

If you make use of any of the Toolkit in your research please acknowledge using:

This work makes use of the Black Hole Perturbation Toolkit.

To cite the Toolkit please use this BibTeX entry (or similar). Some modules also request additional citations. Please check the documentation for individual modules.