CosmoMC and CMB normalization
Posted: August 13 2005
Hi,
I have modified CAMB to directly integrate an inflation model, which provides the correct normalization for the curvature perturbation. I've also modified CosmoMC to have additional InitialPower parameters, and (I think) correctly modified params.ini to use them, in the following way, e.g.:
from params.ini, for five additional parameters:
#new param1
param8 = blah blah blah blah blah
#new param2
param9 = blah blah blah blah blah
#new param3
param10 = blah blah blah blah blah
#new param4
param11 = blah blah blah blah blah
#new param5
param12 = blah blah blah blah blah
#params below are unused by the new version:
#log[10^10 A_s]
param13 = 742.562 742.562 742.562 0 0
#amp_ratio
param14 = 0 0 0 0 0
#unused fast parameter
param15 = 0 0 0 0 0
My reasoning for setting param13 was that since the primodial spectrum is supplied to CAMB in proper dimensionless units, I just need As to be (T_cmb)^2 to convert it into \mu K^2 (i.e. this is the number I would normally put in CMB_outputscale in CAMB's params.ini).
Then in settings.f90 I have asked for 5 InitialPower parameters, and in params_CMB.f90 I've modified for example:
!HVP
else if (Power_Name == 'infl_model') then
P%InitPower%ScalarPowerAmp(in)=cl_norm*CMB%norm(norm_As)
P%InitPower%infl_1 = CMB%InitPower(1)
P%InitPower%infl_2 = CMB%InitPower(2)
P%InitPower%infl_3 = CMB%InitPower(3)
P%InitPower%infl_4 = CMB%InitPower(4)
P%InitPower%infl_5 = CMB%InitPower(5)
!END HVP
Unfortunately CAMB does not seem to be called properly with these modifications and exits with an error from the primordial PS calculation. CAMB works fine for this modification when invoked directly rather than from CosmoMC.
Could someone please let me know if I have made an incorrect modification, or whether there is something else I need to add?
Thanks a lot,
Hiranya
I have modified CAMB to directly integrate an inflation model, which provides the correct normalization for the curvature perturbation. I've also modified CosmoMC to have additional InitialPower parameters, and (I think) correctly modified params.ini to use them, in the following way, e.g.:
from params.ini, for five additional parameters:
#new param1
param8 = blah blah blah blah blah
#new param2
param9 = blah blah blah blah blah
#new param3
param10 = blah blah blah blah blah
#new param4
param11 = blah blah blah blah blah
#new param5
param12 = blah blah blah blah blah
#params below are unused by the new version:
#log[10^10 A_s]
param13 = 742.562 742.562 742.562 0 0
#amp_ratio
param14 = 0 0 0 0 0
#unused fast parameter
param15 = 0 0 0 0 0
My reasoning for setting param13 was that since the primodial spectrum is supplied to CAMB in proper dimensionless units, I just need As to be (T_cmb)^2 to convert it into \mu K^2 (i.e. this is the number I would normally put in CMB_outputscale in CAMB's params.ini).
Then in settings.f90 I have asked for 5 InitialPower parameters, and in params_CMB.f90 I've modified for example:
!HVP
else if (Power_Name == 'infl_model') then
P%InitPower%ScalarPowerAmp(in)=cl_norm*CMB%norm(norm_As)
P%InitPower%infl_1 = CMB%InitPower(1)
P%InitPower%infl_2 = CMB%InitPower(2)
P%InitPower%infl_3 = CMB%InitPower(3)
P%InitPower%infl_4 = CMB%InitPower(4)
P%InitPower%infl_5 = CMB%InitPower(5)
!END HVP
Unfortunately CAMB does not seem to be called properly with these modifications and exits with an error from the primordial PS calculation. CAMB works fine for this modification when invoked directly rather than from CosmoMC.
Could someone please let me know if I have made an incorrect modification, or whether there is something else I need to add?
Thanks a lot,
Hiranya