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lesgourg / class_public

Public repository of the Cosmic Linear Anisotropy Solving System (master for the most recent version of the standard code; GW_CLASS to include Cosmic Gravitational Wave Background anisotropies; classnet branch for acceleration with neutral networks; ExoCLASS branch for exotic energy injection; class_matter branch for FFTlog)
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Constraining CLP model #524

Open COSMOLEARNER opened 1 year ago

COSMOLEARNER commented 1 year ago

Hi, I am very new to CLASS. I would like to constrain the CLP model with Pantheon and Planck 2018 data sets. I am quite confused about whether I need to set Omega_Lambda=0 and leave Omega_fld unspecified in the explanatory.in file, or if I need to add data.cosmo_arguments['Omega_Lambda'] = 0.0 in the .param file in Montepython. Do I need to do both of these changes in the explanatory.in and .param files?

Thanks and regards

brinckmann commented 1 year ago

Hi,

You need to fix Omega_Lamda = 0 in the param file in MontePython in the way you mention (or in the ini file if you want to run only CLASS, but it isn't used when running through MontePython), so CLASS goes into the if statement looking for fld species. You can leave Omega_fld unspecified and instead set w0_fld and wa_fld since you mention you're interested in the CPL parameterization. See, e.g., this MontePython issue https://github.com/brinckmann/montepython_public/issues/280

You'll also need to set priors on the parameters in order to properly explore parameter space without errors, see, e.g., MontePython issue https://github.com/brinckmann/montepython_public/issues/212

Best, Thejs