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Clone wikicosmosis / default_modules / class_2.4.1
class module
Boltzmann and background integrator for BG, CMB, matter power, and more
Name: class
File: cosmosis-standard-library/boltzmann/class/class_interface.py
Version: 2.4.1
Author(s):
- Julien Lesgourgues
- Thomas Tram
- Benjamin Audren
- Simon Prunet
- Jesus Torrado
- Miguel Zumalacarregui
- etc
URL: http://class-code.net
Cite:
- http://arxiv.org/abs/1104.2932
- JCAP 07 (2011) 034
- http://arxiv.org/abs/1104.2934
- JCAP 09 (2011) 032
Rules:
- You can use CLASS freely, provided that in your publications, you cite at least the paper CLASS II: Approximation schemes. Feel free to cite more CLASS papers!
Assumptions:
- The LCDM model
- Various choices for approximations and implementations of the Boltzmann and related equations
Explanation
CLASS is one of the standard cosmology codes for evolving perturbations
in the primordial universe into CMB and other power spectra, as
well as various other quantities. This is a very preliminary interface
to the general and powerful CLASS code.
See http://class-code.net for a fuller description and the github repository
https://github.com/lesgourg/class_public for the latest public code.
You should also check out the MontePython sampler code, which uses CLASS
to do similar inference to CosmoSIS.
This version of CLASS has been modified very slightly to be able to output at
more redshifts and to use the cosmosis build system.
The CosmoSIS team packaged this module into cosmosis form so any issues
running it here please ask us first.
##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.
| Parameter | Description |
|---|---|
| lmax | Integer, max angular frequency ell to use for cmb calculation (default 2000) |
| kmax | Integer, the max wavenumber k to use for P(k,z) calculation (default 50.0) |
| zmax | Max value to save P(k,z) and distances (default 4.0) |
##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.
| Section | Parameter | Description |
|---|---|---|
| cosmological_parameters | ombh2 | real, physbaryon density fraction today, Omega_b * h**2 |
| omch2 | real, physical cdm density fraction today, Omega_c * h**2 | |
| h0 | real, hubble parameter H0 / 100 km/s/Mpc | |
| tau | real, optical depth to last-scattering | |
| n_s | real, scalar spectral index | |
| A_s | real, scalar spectrum primordial amplitude | |
| massless_nu | real, effective number of massless neutrinos (default 3.046) | |
| t_cmb | real, the CMB temperature today in Kelvin (default=2.726) |
##Outputs
These parameters and data are computed as outputs from the module
| Section | Parameter | Description |
|---|---|---|
| cosmological_parameters | sigma_8 | real, amplitude of linear matter power at 8/h Mpc at z=0. Only calculated if mode=all |
| distances | nz | integer, number of z samples |
| z | 1D real array, redshifts of samples | |
| d_a | 1D real array, angular diameter distance in Mpc | |
| d_m | 1D real array, co-moving distance in Mpc | |
| d_l | 1D real array, luminosity distance in Mpc | |
| age | real, age of universe in GYr | |
| rs_zdrag | real, sound horizon size at zdrag. Only if mode!=background | |
| matter_power_lin | z | 1D real array, redshifts of samples. Only if mode=all |
| k_h | 1D real array, k wavenumbers of samples in Mpc/h. Only if mode=all | |
| p_k | 2D real array, matter power spectrum at samples in (Mpc/h)^-3. Only if mode=all | |
| cmb_cl | ell | 1D integer array, angular frequencies. Only if mode=cmb or all |
| tt | 1D real array, ell * (ell+1) C_ell^TT / 2 pi in mu K^2. Only if mode=cmb or all | |
| ee | 1D real array, ell * (ell+1) C_ell^EE / 2 pi in mu K^2. Only if mode=cmb or all | |
| bb | 1D real array, ell * (ell+1) C_ell^BB / 2 pi in mu K^2. Only if mode=cmb or all | |
| te | 1D real array, ell * (ell+1) C_ell^TE / 2 pi in mu K^2. Only if mode=cmb or all |
Updated