py21cmEMU 3.0.0

Emulator of 21cmFAST summaries.

A 21cmFAST emulator of the first billion years

An emulator of 21cmFAST summaries, supporting three galaxy-formation models:

• ACG (v1; Breitman+23) — Atomic Cooling Galaxies (Pop II only). A 9-parameter emulator for the standard reionization scenario without mini-halos.
• radio (v2; Cang+24) — Radio Background. A 5-parameter emulator that adds a radio background sourced by molecular cooling (Pop III) stars on top of atomic cooling galaxies.
• MCG (v3; Breitman+26) — Molecular Cooling Galaxies. The most complete 11-parameter emulator, jointly modelling atomic and molecular cooling galaxies (Pop II + Pop III). Uniquely emulates the 2D cylindrical power spectrum P(k_⊥, k_∥) via a score-based diffusion model.

Emulated summary statistics per model

Output	acg (v1)	radio (v2)	mcg (v3)
Global brightness temperature Tb	✓	✓	✓
Neutral fraction xHI	✓	✓	✓
Thomson optical depth τ	✓	✓	✓
IGM spin temperature Ts	✓	✗	✓
Radio temperature Tr	✗	✓	✗
1D power spectrum P(k)	✓	✓	✓
2D power spectrum P(k⊥, k∥)	✗	✗	✓
UV luminosity functions	✓	✗	✓

Documentation

See the documentation for tutorials and API.

Issues

If you encounter any problems, please file an issue along with a detailed description.

Contributing

Contributions are very welcome. To learn more, see the Contributor Guide.

Citation

If you use 21cmEMU in your research, please cite Breitman+23. In particular, if you use 21cmEMUv2, also cite Cang+24. If you use the newest mcg/v3 emulator, please also cite Breitman+26.

License

Distributed under the terms of the MIT license, 21cmEMU is free and open source software.