A python package for extracting quasinormal modes from black-hole ringdown simulations.

Key Features

• Fit a ringdown waveform with quasinormal modes (QNMs) of fixed or free frequencies
• Nonlinear least-squares fitting with automatic differentiation via JaxFit
• Agnostic identification of QNMs within the waveform
• Saving and reusing results with pickle
• Easy visualization of results
• Call hyperfit polynomials to approximate QNM amplitudes in the ringdown of binary black hole (BBH) mergers

Installation

pip install jaxqualin

Usage

Basic usage examples can be found under the Examples tab on the left.

Note We did not extensively test and do not recommend running jaxqualin on a GPU

Paper Results

Interactive plots of the methods paper results can be found under the Results tab on the left.

Coming Soon

• Full API
• Support for real (Schwarzshild) ringdown waveforms
• Fitting for the mass and spin of the remnant

How to Cite

Please cite the methods paper if you used our package to produce results in your publication. Here is the BibTeX entry:

@misc{cheung2023extracting,
      title={Extracting linear and nonlinear quasinormal
      modes from black hole merger simulations}, 
      author={Mark Ho-Yeuk Cheung and Emanuele Berti and 
      Vishal Baibhav and Roberto Cotesta},
      year={2023},
      eprint={2310.04489},
      archivePrefix={arXiv},
      primaryClass={gr-qc}
}

License

MIT

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GitHub @mhycheung