no_bias module

Generate galaxy power P(k) as though galaxies were unbiased DM tracers

Name: no_bias

File: cosmosis-standard-library/bias/no_bias/no_bias.py

Version: 1

Author(s):

• CosmoSIS Team

URL:

Cite:

Rules:

Assumptions:

• Unit galaxy bias; at all scales and redshifts galaxies perfectly trace dark matter

Explanation

Galaxy bias relates the distribution of galaxies to the underlying (dark) matter
field whose skeleton they trace.

The matter power spectrum of galaxies is related to that of matter by a bias:

P_gal(k,z) = b(k,z,...) P_m(k,z)

where the most general bias is a function of wavenumber k, redshift z, galaxy type,
and a whole host of other values. Realistic bias models can be complicated; the purpose
of this module is to act as a placeholder, usually when testing pipelines or forecasting.

In this module, b=1. It generates the galaxy power and
matter-galaxy cross-power from the non-linear power spectrum, just by copying them.

Optionally, if it finds you have generated the matter-intrinsic alignment cross-power,
it will calculate the galaxy-intrinsic cross power from it.

##Parameters

These parameters can be set in the module's section in the ini parameter file.
If no default is specified then the parameter is required.

##Inputs

These parameters and data are inputs to the module, either supplied as parameters by the sampler or computed by some previous module. They are loaded from the data block.

##Outputs

These parameters and data are computed as outputs from the module