CosmoMC warning: mismatch in integrated times (CAMB: CalcScalarSources)

Use of Cobaya. camb, CLASS, cosmomc, compilers, etc.
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srijita sinha
Posts: 29
Joined: April 12 2019
Affiliation: Indian Institute of Science Education and Research Kolkata

CosmoMC warning: mismatch in integrated times (CAMB: CalcScalarSources)

Post by srijita sinha » November 18 2020

Hi,

In one of my CosmoMC, it is giving the warning message:

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WARNING: mismatch in integrated times (CAMB: CalcScalarSources)
but there is no error message in the chains log file. This error is staring after

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 Current convergence R-1 =   0.2225066      chain steps =        6010
I could not understand anything from cmbmain.f90 file.

In another, there is no warning or error message from CosmoMC, but the chains-2 and 3 log files are showing:

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CAMB called 19500 times; 3 errors
.
This error is staring after around 16600 times of CAMB.

I am using only Planck likelihood and both of the CosmoMCs are for a dynamical DE model with CPL parameterization. I cannot understand what is going wrong in either of them.

Please help.
Srijita

Antony Lewis
Posts: 1719
Joined: September 23 2004
Affiliation: University of Sussex
Contact:

Re: CosmoMC warning: mismatch in integrated times (CAMB: CalcScalarSources)

Post by Antony Lewis » November 18 2020

It's probably harmless as the error is triggered for relatively low errors - likely caused by the non-LCDM background requiring tighter timesteps to do the integration very accurately. You can test and fine-tune CAMB's accuracy parameters for your model before running CosmoMC if you want to be sure.

srijita sinha
Posts: 29
Joined: April 12 2019
Affiliation: Indian Institute of Science Education and Research Kolkata

Re: CosmoMC warning: mismatch in integrated times (CAMB: CalcScalarSources)

Post by srijita sinha » November 18 2020

Thank you for your reply.

srijita sinha
Posts: 29
Joined: April 12 2019
Affiliation: Indian Institute of Science Education and Research Kolkata

Re: CosmoMC warning: mismatch in integrated times (CAMB: CalcScalarSources)

Post by srijita sinha » November 20 2020

Hi,

There are certain parameter values for which the following error is being generated:

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-0.996198831932876       1.071091424913879E-002
CAMB returned error HMCode INTEGRATE, Integration timed out
where the 2 values are for [math] and [math] of the CPL parametrization. These values do not give the best results when checked in CAMB. I made the CosmoMC to not stop at those errors.

These points are not rejected from the MCMC chain. How to make these points rejected? Or their presence in the MCMC chain is not a problem? These points are resulting in error msg in the log file:

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CAMB called 10600 times; 60 errors
etc.

What to do?

As discussed in viewtopic.php?f=11&t=94&p=6982&hilit=savvas#p6982, I need to add

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use Errors
in Calculator_CAMB.f90? But I cannot find any module named

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Errors.
What am I missing?

Is there any thumb rule of setting the upper and lower limits of the parameters, if I have the best-fit values?

Sorry if these have already been discussed. Any help would be great!

Srijita

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