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mgcamb module
Modified Gravity Boltzmann and background integrator for BG, CMB, and matter power
Name: mgcamb
File: cosmosis-standard-library/boltzmann/mgcamb/camb.so
Version: Feb14
Author(s):
- A. Hojjati
- G.B. Zhao
- L. Pogosian
- A. Silvestri
- Antony Lewis
- Anthony Challinor
URL: http://www.sfu.ca/~aha25/MGCAMB.html
Cite:
Rules:
- Please abide by the conditions set out in the CAMB license if you use this module http://camb.info/CAMBsubmit.html
Assumptions:
- One of several modification ansatzes specifying changes from GR
- wCDM background evolution
- Other camb assumptions
Explanation
See the CAMB module for a general introduction to CAMB.
MGCAMB is a modified version of CAMB in which the linearized
Einstein equations of General Relativity (GR) are modified.
It implements several different parameterizations, which are described on this page:
http://www.sfu.ca/~aha25/Models.html
and referred to here as:
model 0 : default GR
model 1 : BZ(mu,gamma) ( introduced in arXiv:0801.2431)
model 2 : (Q,R) ( introduced in arXiv:1002.4197 )
model 3 : (Q0,R0,s)( introduced in arXiv:1002.4197 )
model 4 : f(R) ( introduced in arXiv:0909.2045 )
model 5 : Chameleon ( introduced in arXiv:0909.2045 )
model 6 : Linder's gamma (introduced in arXiv:0507263 )
##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. |
| mg_model | Integer, from 0-6, choice of MG model to use |
| 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 | Min value to save P(k,z) (default 0) |
| zmax | Max value to save P(k,z) (default 4) |
| nz | Number of z values to save P(k,z) (default 401, so that dz=0.01) |
| do_nonlinear | Apply non-linear halofit corrections to matter-power. Relevant only for lensing right now (default F) |
| do_lensing | Include lensing of CMB, and save C_ell phi-phi (default F) |
| high_ell_template | Required for lensing - set to the file included in the camb dir (no default) |
##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 |
|---|---|---|
| modified_gravity | grtrans | real, scale factor of transition from GR |
| b1 | real, model 1, beta 1 in mu(a,k) | |
| b2 | real, model 1, beta 2 in gamma(a,k) | |
| lambda1_2 | real, model 1, lambda_1^2 in mu(a,k) | |
| lambda2_2 | real, model 1, lambda_2^2 in gamma(a,k) | |
| ss | real, model 1, scale factor power index in mu and gamma | |
| MGQfix | real, model 2, Constant Q value | |
| MGRfix | real, model 2, Constant R value | |
| Qnot | real, model 3, Q_0 term in Q(k,a) | |
| Rnot | real, model 3, R_0 term in R(k,a) | |
| sss | real, model 3, scale factor power index for Q and R | |
| b0 | real, models 4 & 5, B_0 term that goes into lambda_1^2 in mu(a,k) | |
| beta1 | real, model 5, beta_1 term that goes into lambda_2^2 term in mu(a,k) | |
| s | real, model 5 scale factor power index for mu | |
| linder_gamma | real, model 6, gamma_L power law in Omega_M for growth rate | |
| 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) | |
| wa | real, equation of state parameter w(z) = w_0 + w_a z / (1+z) (default 0.0) | |
| cs2_de | real, dark energy sound speed/c (default 1.0) |
##Outputs
These parameters and data are computed as outputs from the module
| Section | Parameter | Description |
|---|---|---|
| post_friedmann_parameters | z | 1D real array, redshifts of samples |
| k_h | 1D real array, k wavenumbers of samples in Mpc/h. | |
| D | 2D real array, D(k,z) modification to first perturbed Einstein equation | |
| Q | 2D real array, Q(k,z) modification to first perturbed Einstein equation | |
| 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 | |
| PhiPhi | 1D real array, Lensing spectrum; note ell scaling: ell * (ell+1) C_ell^PhiPhi. Only if mode=cmb or all |
Updated