### COBAYA+CAMB marginalizing over DE models

Posted:

**June 22 2023**Hi all,

I am trying to figure out whether there is any chance in Cobaya+CAMB to do the following:

I would like to include a discrete parameter, le's say [math]={0,1}, to switch between the dark energy model in CAMB between standard LCDM and EarlyQuintessence; the idea would be to sample over it at runtime. I am not sure there is a trivial way to do so, since the dark energy model is fixed by CAMB extra_args in the input yaml file; ideally, it should be dropped and this choice should be make dependent on the extra parameter [math]- defined in the param block of the same .yaml - in the theory code.

Does anybody of you know whether this is doable in some relatively easy way in Cobaya/CAMB, or have any suggestion?

Thanks,

Simone

I am trying to figure out whether there is any chance in Cobaya+CAMB to do the following:

I would like to include a discrete parameter, le's say [math]={0,1}, to switch between the dark energy model in CAMB between standard LCDM and EarlyQuintessence; the idea would be to sample over it at runtime. I am not sure there is a trivial way to do so, since the dark energy model is fixed by CAMB extra_args in the input yaml file; ideally, it should be dropped and this choice should be make dependent on the extra parameter [math]- defined in the param block of the same .yaml - in the theory code.

Does anybody of you know whether this is doable in some relatively easy way in Cobaya/CAMB, or have any suggestion?

Thanks,

Simone