CosmoFit.CPL

class CosmoFit.CPL(params)[source]

Bases: Cosmology

Chevallier-Polarski-Linder (CPL) dark-energy model.

Equation of state

w(z) = w0 + wa * z / (1 + z)

Parameters:

params (CosmologyParameters)

__init__(params)
Parameters:

params (CosmologyParameters)

Methods

E(z)

Dimensionless Hubble parameter.

H(z)

Omega_de(z)

Dark-energy density parameter.

Omega_matter(z)

Matter density at redshift z, in units of today's critical density -- i.e. the Omega_m (1+z)^3 term as it appears inside E(z)^2, before dividing by E(z)^2.

__init__(params)

dEdz(z)

Derivative of E(z).

fde(z)

Dark-energy density evolution factor.

mu(a[, k])

Effective-to-Newtonian gravitational coupling ratio, G_eff(a,k)/G_N, entering the linear growth equation solved by GrowthCalculator (see that module's docstring for the equation itself).

plain_name()

This model's name as plain text: MODEL_NAME if it declares one, else the class name.

plot_label()

This model's name as it should appear in a figure legend or title -- MODEL_LABEL (LaTeX) if it declares one, else plain_name().

refresh()

Rebuild internal numerical tables after the underlying params object has been mutated in place (e.g. by params.update(theta) during an MCMC step).

w(z)

Dark-energy equation of state.

Attributes

A_planck

A_s

EXTRA_PARAMS

Extra parameters this model adds beyond CosmologyParameters.

H0

MB

MODEL_LABEL

a LaTeX math string where the plain name is really a set of symbols (LCDM -> $\Lambda$CDM), None where the plain name is already what a reader should see (an acronym like CPL).

MODEL_NAME

Plain-text name for this model, for tables, JSON and log lines.

N_eff

Omega_b

Omega_de0

Omega_k

Omega_m

alpha

compute_rd

Whether rd is computed from the physical densities (rd_computed()) rather than read from the free rd parameter.

derive_sigma8

Whether sigma8 is derived from the Boltzmann code rather than read from the free sigma8 parameter.

h

Reduced Hubble constant, H0 / 100.

ln1e10As

m_nu

n_s

omega_b_h2

Physical baryon density, Omega_b h^2 -- the combination BBN and the CMB actually constrain.

omega_cdm_h2

Physical cold dark matter density, Omega_c h^2 -- matter less baryons.

omega_m_h2

Physical matter density, Omega_m h^2.

rd

The sound horizon at the drag epoch [Mpc] that the BAO likelihoods divide by.

sigma8

Present-day sigma_8, the normalization every growth prediction is built on.

tau_reio

w0

wa