CAMB: extended version

Use of Healpix, camb, CLASS, cosmomc, compilers, etc.
Post Reply
Francesca Schiavon
Posts: 1
Joined: June 30 2011
Affiliation: University of Bologna

CAMB: extended version

Post by Francesca Schiavon » July 07 2011

Dear all,
I would like to use the extended version of CAMB ( which also gives the theoretical cl ISW-LSS but I have some doubts about the outputs of the code. If the params.ini is as attached below, which is the ISW-LSS cross-correlation column in the output file (C_Phi C_PhiT C_win_1 C_win_2... C_Win_T1 C_Win_T2 .... C_win1_win2 ...)?

And about this, how to set the count_* parameters to have just ISW? Do I have to put just

count_ISW = T


If I wish to consider a 'mean' redshift = 1 and a bias term = 1.98, should I consider

redshift_bias(1) = 1.98


And how can I take into account the window function of the survey? with the redshift_sigma(1)?

Another issue is the units of the angular power spectrum of the cross-correlations (which I understand as band powers, right?).



#Parameters for CAMB with 21cm, lensing and number counts

#output_root is prefixed to output file names
output_root = test

#for 21cm C_l with sharp window use get_transfer=T, transfer_21cm_cl=T
#for broad window and other sources use get_scalar_cls=T
get_scalar_cls = T
get_transfer = F
get_vector_cls = F
get_tensor_cls = F

want_CMB = T

#Whether transfer functions are 21cm (monopole and velocity), or standard
Do21cm = F

#l_max_scalar = 10000
#for 21cm k_eta_max_scalar need to be at least 5000; for lensing is re-set automatically
#k_eta_max_scalar = 20000
l_max_scalar = 2000
k_eta_max_scalar = 4000

# 0: linear, 1: non-linear matter power (HALOFIT), 2: non-linear C_l (HALOFIT approx)
#Or compile with NONLINEAR = nonlinear_PT to use perturbation theory, e.g. for 21cm non-linear approx
do_nonlinear = 0

#only use limber approx if you don't want cross-correlation
limber_windows = F

#output 21cm spectra in mK (rather than dimensionless)
use_mK = F

### 21cm ###
line_basic = F
line_distortions = F
line_extra = F
line_phot_quadrupole = F
line_phot_dipole = F
line_reionization = F

#### number counts ####
#whether spectra include lensing effect
DoRedshiftLensing = T

counts_density = T
counts_redshift = F
counts_radial = F
counts_timedelay = F
counts_ISW =T
counts_velocity =F
counts_potential = F

#counts_evolve =T allows for non-constant comoving source density
#uses function counts_background_z in modules_redshift space;
#if T by default assumes window includes all sources; if F then assumes constant comoving source density
counts_evolve = F

### window functions ###

#Number of z-windows to use for sources. assumed Gaussian - edit Window_f_a in modules.f90.
num_redshiftwindows = 1

#Set of indexed parameters for each window function

#Redshift of the window for C_l

redshift(1) =50
# 21cm, counts or lensing
redshift_kind(1) = counts
# if 21cm, width of T_b window in Mhz
redshift_sigma_Mhz(1) = 0.01

#if not 21cm, width in z
redshift_sigma(1) = 1

#if counts (change redshift_kind(1)), the bias
redshift_bias(1) = 4.5
#for counts magnitude-limited survey; often called s or p, assumed constant
redshift_dlog10Ndm(1) = 0.42

massless_neutrinos = 3.04
massive_neutrinos = 0
nu_mass_eigenstates = 1
nu_mass_degeneracies = 1
#nu_mass_fractions = .4285714286 .5714285714
nu_mass_fractions = 1
#massive_nu_approx: 0 - integrate distribution function
# 1 - switch to series in velocity weight once non-relativistic
# 2 - use fast approximate scheme (CMB only- accurate for light neutrinos)
massive_nu_approx = 3

#Settings for transfer functions/matter power spectrum/21cm sharp-z power spectrum
transfer_high_precision = T
transfer_kmax = 500
transfer_k_per_logint = 0
transfer_num_redshifts = 1
transfer_redshift(1) = 50

#Whether to compute 21cm C_l from transfer functions for sharp redshift window
#using only monopole source and redshift distortions
transfer_21cm_cl = F

#Whether to turn off small-scale late time radiation hierarchies (save time,v. accurate)
# not tested with redshift window functions
do_late_rad_trunction = F

RECFAST_fudge = 1.14

#if do_lensing then scalar_output_file contains additional columns of l^4 C_l^{pp} and l^3 C_l^{pT}
#where p is the projected potential. Output lensed CMB Cls (without tensors) are in lensed_output_file below.
do_lensing = F

#Maximum multipole and k*eta.
# Note that C_ls near l_max are inaccurate (about 5%), go to 50 more than you need
# Lensed power spectra are computed to l_max_scalar-250 where accurate at %-level
# For high accuracy lensed spectra set l_max_scalar = (l you need) + 500
# To get accurate lensed BB need to have l_max_scalar>2000,
k_eta_max_scalar > 10000
# Otherwise k_eta_max_scalar=2*l_max_scalar usually suffices
# Tensor settings should be less than or equal to the above
l_max_tensor = 500
k_eta_max_tensor = 4000

#Main cosmological parameters, neutrino masses are assumed degenerate
# If use_phyical set phyiscal densities in baryone, CDM and neutrinos + Omega_k
use_physical = F
#ombh2 = 0.223253E-01
#omch2 = 0.104284E+00
#omk = 0
#omnuh2 = 0
hubble = 0.731586E+02
#effective equation of state parameter for dark energy, assumed
constant w = -1
#constant comoving sound speed of the dark energy (1=quintessence) cs2_lam = 1

#if use_physical = F set parameters as here
omega_baryon = 0.0462
omega_cdm = 0.2538
omega_lambda = 0.7
omega_neutrino = 0

#massless_neutrinos is the effective number (for QED + non-instantaneous decoupling)
temp_cmb = 2.725
helium_fraction = 0.24

#Reionization (assumed sharp), ignored unless reionization = T
reionization = T
re_use_optical_depth = T
re_optical_depth = 0.912305E-01
#If re_use_optical_depth = F then use following, otherwise ignored
re_redshift = 12
re_ionization_frac = 1

#Initial power spectrum, amplitude, spectral index and running
initial_power_num = 1
scalar_amp(1) = 2.0424e-009
scalar_spectral_index(1) = 0.954663E+00
scalar_nrun(1) = 0
tensor_spectral_index(1) = 0
#ratio is that of the initial tens/scal power spectrum amplitudes
initial_ratio(1) = 0.1
#note vector modes use the scalar settings above

#Initial scalar perturbation mode (adiabatic=1, CDM iso=2, Baryon iso=3,
#neutrino density iso =4, neutrino velocity iso = 5)
initial_condition = 1
#If above is zero, use modes in the following (totally correlated)
#Note: we assume all modes have the same initial power spectrum
initial_vector = -1 0 0 0 0

#For vector modes: 0 for regular (neutrino vorticity mode), 1 for magnetic
vector_mode = 0

COBE_normalize = F
##CMB_outputscale scales the output Cls
#To get MuK^2 set realistic initial amplitude (e.g. scalar_amp(1) = 2.3e-9
above) and
#otherwise for dimensionless transfer functions set scalar_amp(1)=1 and use
CMB_outputscale = 1
#CMB_outputscale = 7.4311e12

#Transfer function settings, transfer_kmax=0.5 is enough for sigma_8
transfer_filename(1) =
#Matter power spectrum output against k/h in units of h^3 Mpc^{-3}
transfer_matterpower(1) =
#21cm C_l for sharp window
transfer_cl_filename(1) =

#Output files not produced if blank. make camb_fits to use use the FITS
scalar_output_file = scalCls.dat
scalar_covariance_output_file = scalCovCls.dat
vector_output_file = vecCls.dat
tensor_output_file = tensCls.dat
total_output_file = totCls.dat
lensed_output_file = lensedCls.dat
FITS_filename = scalCls.fits

##Optional parameters to control the computation speed,accuracy and feedback

#If feedback_level > 0 print out useful information computed about the model
feedback_level = 1

# 1: curved correlation function, 2: flat correlation function, 3: inaccurate harmonic method
lensing_method = 1
accurate_BB =T

#Recombination calculation: 1: RECFAST, 2: RECFAST+astro-ph/0501672
recombination = 1

#Whether you are bothered about polarization.
accurate_polarization = T

#Whether you are bothered about percent accuracy on EE from reionization
accurate_reionization = T

#whether or not to include neutrinos in the tensor evolution equations
do_tensor_neutrinos = F

#if true, get accurate gas temperature evolution given recombination model including
#approximate perturbed recombination; also affects baryons for k >~ 300/Mpc.
evolve_delta_xe = F

#Computation parameters
#if number_of_threads=0 assigned automatically
number_of_threads = 0

#Default scalar accuracy is about 0.3% (except lensed BB).
#For 0.1%-level try accuracy_boost=2, l_accuracy_boost=2.

#Increase accuracy_boost to decrease time steps, use more k values, etc.
#Decrease to speed up at cost of worse accuracy. Suggest 0.8 to 3.
accuracy_boost = 1

#Larger to keep more terms in the hierarchy evolution.
l_accuracy_boost = 1

#Increase to use more C_l values for interpolation.
#Increasing a bit will improve the polarization accuracy at l up to 200 -
#interpolation errors may be up to 3%
#Decrease to speed up non-flat models a bit
l_sample_boost = 1

Antony Lewis
Posts: 1379
Joined: September 23 2004
Affiliation: University of Sussex

Re: CAMB: extended version

Post by Antony Lewis » July 08 2011

Win_T1 is the correlation of the CMB temperature with the first window.
The CMB here includes everything, but most of the correlation is from ISW. You'd have to edit the output routine in equations.f90 if you just want the ISW term in the CMB. I suggest you use the scalar_covariance_output_file output as it is much easier to figure out which column is which output.

counts_ISW includes the ISW term in the counts (very small effect).

The redshift_sigma parameter sets the width for a Gaussian window function, or you can change the window function in the code.

Post Reply