w0wa_sum_prior

Skip parameter sample without failing if w0+wa>0.

File	utility/exclude_w0_wa/w0wa_sum_prior.py
Attribution	Jessie Muir
URL

This module imposes a the requirement that w_0+w_a<0, which ensures that w(a)= w_0 + (1-a)w_a is always negative.

This is useful because it allows us to avoid computational problems that

CAMB (and possibly other boltzman codes) has when the dark energy equation of state becomes positive.

This module checks whether w_0+w_a<0. If that condition is fulfilled, the module does nothing. If w_0+w_a>=0, the module returns 1, which will cause cosmosis samplers to throw out the point and skip the rest of the pipeline for that sample.

Assumptions

• Cosmological parameters include w and wa.

Setup Parameters

Name	Type	Default	Description
verbose	bool	False	Whether to print an error message noting when points fail the w_0+w_a<0 requirement

Input values

Section	Name	Type	Default	Description
cosmological_parameters	w	real		Dark energy equation of state at z=0 (w_0)
	wa	real		Linear coefficient of dark energy equation of state on scale factor

Output values

None