Cobaya: control nonlinear corrections

[Zhuangfei Wang]

Hello:

I just have a question about how to control whether to use nonlinear correction globally in a convenient way in Cobaya, I noticed that in CosmoMC we have such commands in .ini files:

use_nonlinear_lensing = T
nonlinear_pk = F

Is there a way to do the same in Cobaya? Particularly, is it possible to set in "extra_args" under the camb block in input.yaml? Thanks.

[Antony Lewis]

For lensing the lens_potential_accuracy parameter greater than zero sets non-linear lensing. For the power spectrum, it's up to each likelihood to request the power spectrum if they need it, and specify linear if they only need linear. If you're asking if there is a way to force likelihoods to get linear spectra even if they request non-linear, I think the answer is probably no without code changes.

[Zhuangfei Wang]

Thanks a lot, Antony. It is very useful to know this.