CosmoCoffee

Posted: **August 22 2020**

Hi,

I am a novice in CosmoMC and please pardon if it is a trivial question and already answered.

I want to constrain the six parameter

\LambdaCDM model with fsigma8 data given in table: III of https://arxiv.org/abs/1703.10538.
For that, I have written a likelihood similar to bao.f90. When I am using only the fsigma8 data with action = 2, I am getting the minimum values. But when I am using it with action = 0, it is not constraining

n_s,

\tau and

\log A well. The contour plots look blotchy even after increasing the range. The code stops with the error

Code: Select all

CAMB error ThemoData Init: failed to find the end of recombination

When I am using both Planck 2018 and fsigma8, I am getting nice contours but the error message,

Code: Select all

Warning: xe at redshift zero is < 1

Check input parameters a Reionization_xe

function in the Reionization module

is there.
I understand it is related to CAMB. What is it that I need to take care?
I did not change any parameter value given in CosmoMC May 2020.

Thanks in advance.

Posted: **August 22 2020**

If you are only using fsigma8 you should fix unconstrained parameters.

The second message is probably harmless, though that should not happen at all often with Planck data.

Posted: **August 22 2020**

Thanks for the reply

I am using the default Theta parametrization with default params_CMB_default.ini. I only increased the ranges of those parameters (

n_s, \tau, \log A). Which are the unconstraint parameters?

CosmoCoffee

Warning: xe at redshift zero is < 1 in CosmoMC

Warning: xe at redshift zero is < 1 in CosmoMC

Re: Warning: xe at redshift zero is < 1 in CosmoMC

Re: Warning: xe at redshift zero is < 1 in CosmoMC