CLASS_ROT: CLASS for ROTATED CMB POWER SPECTRA

A modified version of the publicly available Einstein-Boltzmann code CLASS to implement Rotated CMB Power Spectra.

See Cai et al. where CLASS_ROT is introduced and tested.

CLASS edited by

• Hongbo Cai; [email protected]
• Yilun Guan; [email protected]

Files

Installation

After cloning or downloading the repository, compile CLASS_ROT with make

$ make

Important Parameters

(1) alpha:

The isotropic cosmic rotation angle

(2) A_cb:

The amplitude of the scale-invariant Gaussian random cosmic rotation power spectrum

(3) input_claa:

The input generic rotation power spectrum

'A_cb' and 'input_claa' should not be given together.

Examples

Python

Jupyter notebooks with worked out examples in Python can be found here.

cl_rot.ipynb is for using a scale-invariant rotation power spectrum.

use_input_claa.ipynb is for using an input generic rotation power spectrum.

cl_rot_lens.ipynb is for generating rotated-lensed Cl, and comparing it with lensed-raw Cl and rotated-raw Cl.

C

CLASS_ROT can be run in C just as normal CLASS. See explanatory-ROT.ini for ROT implementation details.

$ ./class explanatory_ROT.ini

New package added to CLASS

Modifications are explained below.

(1) rotation.c:

This module computes the rotated CMB anisotropy power spectra.

Cite us

If you use our code in a published work, please cite our paper:

@ARTICLE{classrot,
       author = {{Cai}, Hongbo and {Guan}, Yilun},
        title = "{Computing Microwave Background Polarization Power Spectra from Cosmic Birefringence}",
      journal = {arXiv e-prints},
     keywords = {Astrophysics - Cosmology and Nongalactic Astrophysics},
         year = 2021,
        month = nov,
          eid = {arXiv:2111.14199},
        pages = {arXiv:2111.14199},
archivePrefix = {arXiv},
       eprint = {2111.14199},
 primaryClass = {astro-ph.CO},
       adsurl = {https://ui.adsabs.harvard.edu/abs/2021arXiv211114199C},
      adsnote = {Provided by the SAO/NASA Astrophysics Data System}
}