HYREC-2

A code for primordial hydrogen and helium recombination including radiative transfer. An updated version of HyRec with new computing mode. HYREC-2 is implemented in CLASS code as a default module for recombination history since version 3.0.0. HYREC-2 can be used in CAMB code as well.

The original code HyRec developed by Yacine Ali-Haimoud and Chris Hirata (2010-17). HYREC-2 developed with contributions from Nanoom Lee (2020).

Version: July 2020. See readme.pdf for detailed info, and check HYREC-2 paper (Reference 1 below) for the code development.

Installation

• Clone the repo

  git clone https://github.com/nanoomlee/HYREC-2.git

How to run HYREC-2

• Compiling the code

  gcc -lm -O3 hyrectools.c helium.c hydrogen.c history.c energy_injection.c hyrec.c -o hyrec

• Computing a recombination history

  ./hyrec < input.dat

The code will take parameters from input.dat and compute the recombination history. It will print out three columns in output.dat, which are: redshift, free electron fraction, matter temperature in Kelvin. For input parameter description, see input.dat.

References

If you use HYREC-2, please cite the companion papers:

1. N. Lee & Y. Ali-Haimoud, Phys. Rev. D 102 8, 083517 (2020)
2. Y. Ali-Haimoud & C. M. Hirata, Phys. Rev. D 83, 043513 (2011)

You may also refer to the following papers, on which this work relies substantially:

1. Y. Ali-Haimoud & C. M. Hirata, Phys. Rev. D 82, 063521 (2010)
2. C. M. Hirata, Phys. Rev. D 78, 023001 (2008)
3. E. R. Switzer & C. M. Hirata, Phys. Rev. D 77, 083008 (2008)