consistent_parameters module

Deduce missing cosmological parameters and check consistency

Name: consistent_parameters

File: cosmosis-standard-library/utility/consistency/consistency_interface.py

Version: 1.0

Author(s):

• CosmoSIS Team

URL:

Cite:

Rules:

• Please maintain attribution.

Assumptions:

• LCDM parameterization
• First pass: tries no assumptions
• Second pass: tries omega_nu=0
• Third pass: tries omega_nu=0 and omega_k=0

Explanation

There are various ways of parameterizing cosmologies with different advantages
in different contexts. This module takes a set of cosmological parameters and
tries to use them to deduce the remaining parameters. For example, if you specify
ombh2 and h then it computes omega_b. It has a fairly full set of relations to do this.

If you specify inconsistent parameters (e.g. omega values that do not add up to 1)
then an error status is returned.

The following relations are used:

omega_m = ommh2/h/h

omega_b = ombh2/h/h

omega_c = omch2/h/h

omega_nu = omnuh2/h/h

ommh2 = omega_mhh

ombh2 = omega_bhh

omch2 = omega_chh

omnuh2 = omega_nuhh

omch2 = ommh2-ombh2

ommh2 = omch2+ombh2

baryon = omega_b/omega_m

omega_b = omega_m*baryon_fraction

omega_m = omega_b/baryon_fraction

baryon_fraction = ombh2/ommh2

ombh2 = ommh2*baryon_fraction

ommh2 = ombh2/baryon_fraction

omega_m = omega_b+omega_c

h = hubble/100

hubble = h*100

omega_lambda = 1-omega_m-omega_k-omega_nu

omega_m = 1-omega_lambda-omega_k-omega_nu

omega_k = 1-omega_m-omega_lambda-omega_nu

omega_nu = 1-omega_m-omega_lambda-omega_k

##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