PTPlot: About

PTPlot is a tool for exploring the gravitational wave power spectrum from first-order phase transitions, and evaluating the likelihood of detecting a signal with the LISA mission.

About the output

All output figures are Scalable Vector Graphics (SVG) and can be downloaded and edited with free tools such as Inkscape. They are also easily converted to PDF or bitmapped formats by Inkscape or built-in OS tools, e.g.:

$ inkscape input_snr_file.svg --export-pdf=outpout_snr_file.pdf

Note that on Macos, Inkscape requires the full path to the source and destination files in order to work.

Crediting PTPlot

The results plotted by this tool are based on the paper Detecting gravitational waves from cosmological phase transitions with LISA: an update, arXiv:1910.13125. You are welcome to include plots from PTPlot in your own work; if you do use PTPlot, please cite that paper. Figures without the LISACosWG watermark are available on request; please do not remove it without permission.


The source for PTPlot is available at Please do not, however, use this code in your own projects without permission.

Feedback, issues

Please get in touch with the author, David Weir [] or raise an issue on the issue tracker.

Recent news

  • 7.11.2019 - version 1.0.0
    • Coincides with release of paper [arXiv:1910.13125].
    • Source data for plots now included in repo.
    • Minor tick marks now shown.
    • In plotting power spectra, only the sound wave curve is now shown (other curves remain available in the source code).
    • Bugfixes, including: corrections to definition of $\kappa$ and a missing factor of $h^2$ in the sound wave GW power spectrum.
  • 25.6.2019 - version 0.9.5
    • 3- and 7- year mission durations available.
    • Bugfixes to the "energy budget" calculation, which previously had some discrepancies at intermediate velocities.
    • Axis labels cleaned up.
    • "Theories" renamed to "Models" and another layer of granularity, "Scenarios", added to benchmark points.
    • More flexibility in terms of individual points and scenarios having their own $T_*$ and $v_\mathrm{w}$.
    • $\beta/H$ is now plotted (and used as a parameter) rather than $H/\beta$.
  • 21.12.2018 - version 0.9.2
    • The SNR curves and power spectra now use a single merged PowerSpectrum() class.
    • All plots use a conservative form of the sound wave source where it has lifetime set either by the shock formation time or the Hubble time, whichever is shorter.
    • All plots have a date and timestep to assist with debugging.
    • Power spectrum plots have the SNR (from sound waves only) overplotted, too.


  • arXiv:1512.06239 - Science with the space-based interferometer eLISA. II: Gravitational waves from cosmological phase transitions
  • arXiv:1910.13125 - Detecting gravitational waves from cosmological phase transitions with LISA: an update

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