GWInSpect

Gravitational Wave Inflationary Spectra

GWInSpect is a lightweight, research-grade Python package that computes:

• The present-epoch spectral energy density of first-order inflationary gravitational waves, $\Omega_{\rm GW}(f) $, produced by a given (user-defined) post-inflationary expansion history.
• Verifies whether the BBN constraint on (integrated) gravitational wave energy density is satisfied.

📦 Installation

Install GWInSpect by running any one of the following commands in your terminal.

1. ✅ From PyPI (Recommended)

pip install gwinspect

2. 🧪 From GitHub

pip install git+https://github.com/athul104/GWInSpect.git

3. 🛠️ Cloning repo (to make an editable copy of the package in your local system)

git clone https://github.com/athul104/GWInSpect.git
cd GWInSpect
pip install -e .

📋 Requirements

The following necessary libraries will be automatically installed when you install GWInSpect.

• Python 3.9 or later
• numpy >= 1.21
• scipy >= 1.9
• mpmath >= 1.2.0

📓 Tutorial Notebook

The package includes a tutorial notebook under examples/tutorial_gwinspect.ipynb

🧱 Package Structure

Each module is independently documented and demonstrated in the tutorial notebook.

• spectrum.py

  • compute_omega_gw
    Computes $\Omega_{\rm GW}(f)$ for a user defined post-inflationary history of the Universe consisting of a sequence of pre-hot Big Bang epochs, each with a constant equation of state.

• constraints.py

  • check_bbn
    Computes BBN constraint integral piecewise for the user defined sequence of post-inflationary epochs.

• cosmo_tools.py Utilities for cosmological parameter conversions:

  • temp_of_E Convert temperature to energy scale
  • energy_of_T Convert energy scale to temperature
  • freq_of_T Convert temperature to present-day frequency of gravitational waves
  • compute_efolds Compute the duration of each epoch in terms of number of $e$-folds

• thermo.py

  • Functions to compute $g_{*}(T), g_{s}(T)$ from fitting functions given in K. Saikawa and S. Shirai arXiv:1803.01038.
  • Key functions: g_star and g_s
  • Users can also load the pre-computed data of [temperature $T$, $g_{*}(T)$, $g_{s}(T)$, energy($T$)] stored in src\gwinspect\data\eff_rel_dof.txt using load_eff_rel_dof()

• constants.py

  • Contains constants: reduced Planck mass m_P, present CMB temperature T0, scalar amplitude A_S, Present radiation density parameter omega_rad0, BBN temperature T_bbn, matter-radiation equality temperature T_eq
  • Users can also redefine the values of this conatant using set_constants

📚 Citation

This package accompanies the paper:

Swagat S. Mishra & Athul K. Soman (2025)
Morphological Zoo of Inflationary Gravitational Wave Spectra imprinted by a Sequence of Post-Inflationary Epochs
arXiv:2510.25672

If you use GWInSpect in academic work, please cite:

@article{Mishra:2025nnu,
    author = "Mishra, Swagat S. and Soman, Athul K.",
    title = "{Morphological Zoo of Inflationary Gravitational Wave Spectra imprinted by a Sequence of Post-Inflationary Epochs}",
    eprint = "2510.25672",
    archivePrefix = "arXiv",
    primaryClass = "astro-ph.CO",
    month = "10",
    year = "2025"
}

🛠 License

GPL-3.0-or-later
©️ GWInSpect authors (2025)

🙋 Feedback

Thank you for your interest in GWInSpect 💜.
Please report issues or suggestions at: github.com/athul104/GWInSpect/issues