Bases: astropy.cosmology.core.FLRW
FLRW cosmology with a cosmological constant and curvature.
This has no additional attributes beyond those of FLRW.
Examples
>>> from astro.cosmology import LambdaCDM
>>> cosmo = LambdaCDM(H0=70, Om0=0.3, Ode0=0.7)
The comoving distance in Mpc at redshift z:
>>> dc = cosmo.comoving_distance(z)
Methods Summary
de_density_scale(z) | Evaluates the redshift dependence of the dark energy density. |
efunc(z) | Function used to calculate H(z), the Hubble parameter. |
inv_efunc(z) | Function used to calculate \frac{1}{H_z}. |
w(z) | Returns dark energy equation of state at redshift z. |
Methods Documentation
Evaluates the redshift dependence of the dark energy density.
Parameters: | z : array_like
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Returns: | I : ndarray, or float if input scalar
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Notes
The scaling factor, I, is defined by \rho(z) = \rho_0 I, and in this case is given by I = 1.
Function used to calculate H(z), the Hubble parameter.
Parameters: | z : array_like
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Returns: | E : ndarray, or float if input scalar
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Notes
The return value, E, is defined such that H(z) = H_0 E.
Function used to calculate \frac{1}{H_z}.
Parameters: | z : array_like
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Returns: | E : ndarray, or float if input scalar
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Notes
The return value, E, is defined such that H_z = H_0 / E.
Returns dark energy equation of state at redshift z.
Parameters: | z : array_like
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Returns: | w : ndarray, or float if input scalar
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Notes
The dark energy equation of state is defined as w(z) = P(z)/\rho(z), where P(z) is the pressure at redshift z and \rho(z) is the density at redshift z, both in units where c=1. Here this is w(z) = -1.