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camb module
Boltzmann and background integrator for BG, CMB, and matter power
Name: camb
File: cosmosis-standard-library/boltzmann/camb/camb.so
Version: Jan15
Author(s):
- Antony Lewis
- Anthony Challinor
URL: http://camb.info
Cite:
Rules:
- Please abide by the conditions set out in the CAMB license if you use this module http://camb.info/CAMBsubmit.html
Assumptions:
- The wLCDM model
Explanation
The Code for Anisotropies in the Microwave Background, in equations_ppf mode
CAMB is the standard cosmology code for evolving perturbations
in the primordial universe into CMB and matter power spectra, as
well as various auxiliary quantities.
See http://camb.info for a fuller description
It has a wide variety of options only a few of which are currently
exposed here. This will be extended in future. This version of
camb has been modified very slightly to output a few new pieces
of data useful in other modules, notably the dark matter density
history rho(z) (which can vary in non-lcdm models)
Anthony Lewis has kindly given permission for CAMB to be packaged
with CosmoSIS.
If you would like to use the November 2013 version of CAMB instead you can
add camb_Nov13 to the SUBDIRS variable in the boltzmann/Makefile.
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 |
|---|---|
| mode | String, choose from Background, thermal, cmb, or all. In background mode only the expansion history is calculated. In thermal mode the recombination history is computed and rs_zdrag and related quantities also. In cmb mode the CMB power spectra are also calculated. In all mode the matter power spectrum at low redshift and sigma8 are also calculated. |
| lmax | Integer, only if mode!=background, default 1200 - the max ell to use for cmb calculation |
| feedback | Integer, amount of output to print. 0 for no feedback. 1 for basic, 2 for extended, maybe higher? |
| use_tabulated_w | Logical, set to true to load w(z) from previous module (default F) |
| k_eta_max_scalar | Integer, maximum value of (k eta) to evolve for scalars. (default 2*lmax) |
| do_tensors | Include tensor modes (default F) |
| zmin | real, Min value to save P(k,z) (default 0.0) |
| zmax | real, Max value to save P(k,z) (default 4.0) |
| nz | integer, Number of z values to save P(k,z) (default 101, so that dz=0.04) |
| background_zmin | real, Min value to save distance measures (default 0.0) |
| background_zmax | real, Max value to save distance measures (default 4.0) |
| background_nz | integer, Number of z values to save distance measures (default 401, so that dz=0.01) |
| kmin | real, Min wavenumber k to save P(k,z) in h/Mpc (default is camb model-dependent but typically small) |
| kmax | real, Max wavenumber k to save P(k,z) in h/Mpc (default 50.0) |
| nk | integer, Number of k values to save P(k,z) (default is camb-model dependent) |
| do_nonlinear | logical, Apply non-linear halofit corrections to matter-power. Relevant only for lensing right now (default F) |
| do_lensing | logical, Include lensing of CMB, and save C_ell phi-phi (default F) |
| high_ell_template | string, Required for lensing - set to the file included in the camb dir (no default) |
| matter_power_lin_version | bit-field, sum of required matter power spectra. Default is legacy version. |
| accuracy_boost | real, apply an accuracy boost across all calculations. Default=1.0 |
| high_accuracy_default | logical, Change accuracy defaults so that CMB results from ell=500 to ell=2000 are at 0.1% accuracy (usually 0.3%). Default=F |
| reject_non_accelerating | logical, Reject models with w0 + wa > 0. Default=F |
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 | omega_b | real, baryon density fraction today |
| omega_c | real, cdm density fraction today | |
| omega_k | real, curvature density fraction today (default 0.0) | |
| omega_lambda | real, dark energy density fraction today | |
| hubble | real, hubble parameter H0 (km/s/Mpc) | |
| tau | real, optical depth to last-scattering (ignored in background mode) | |
| n_s | real, scalar spectral index (ignored in background/thermal mode) | |
| A_s | real, scalar spectrum primordial amplitude (ignored in background/thermal mode) | |
| k_s | real, Power spectrum pivot scale (default 0.05/Mpc) | |
| r_t | real, tensor to scalar ratio (default 0.0) | |
| n_run | real, running of scalar spectrum d n_s / d log_k (default 0.0) | |
| n_t | real, tensor spectral index (default 0.0) | |
| omega_nu | real, neutrino density fraction today (default 0.0) | |
| massless_nu | real, effective number of massless neutrinos (default 3.046) | |
| massive_nu | integer, number of massive neutrinos (default 0) | |
| sterile_neutrino | integer, number of sterile neutrinos (default 0) | |
| delta_neff | real, contribution to N_eff by sterile neutrino (default 0) | |
| sterile_mass_fraction | real, fraction of omega_nu in sterile neutrino | |
| yhe | real, helium fraction (default 0.24) | |
| w | real, w(z=0) equation of state of dark energy (default -1.0). ignored if use_tabulated_w=T | |
| wa | real, equation of state parameter w(z) = w_0 + w_a z / (1+z) (default 0.0). ignored if use_tabulated_w=T | |
| cs2_de | real, dark energy sound speed/c (default 1.0) | |
| de_equation_of_state_section | a | 1D real array, only used if use_tabulated_w=T. Sample points for generic w(a) |
| w | 1D real array, only used if use_tabulated_w=T. Sample values for generic w(a) |
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 | |
| mu | 1D real array, distance modulus | |
| h | 1D real array, hubble parameter with in units of Mpc | |
| rho | 1D real array, matter density, in kg/m^3. Only if mode=all | |
| age | real, age of universe in GYr | |
| zdrag | real, redshift where baryons no longer dragged by photons. Only if mode!=background | |
| rs_zdrag | real, sound horizon size at zdrag. Only if mode!=background | |
| zstar | real, redshift of unity optical depth. Only if mode!=background | |
| theta | real, angular size of sound horizon at zstar. Only if mode!=background | |
| chistar | real, comoving distance to zstar. 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 | |
| linear_cdm_transfer | 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 | |
| delta_cdm | 2D real array, Linear CDM transfer function at samples. 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 | |
| pp | 1D real array, Phi-Phi lensing spectrum; note ell scaling: ell * (ell+1) C_ell^PhiPhi. Only if mode=cmb or all |
Updated