skypy.power_spectrum.growth_function_carroll

skypy.power_spectrum.growth_function_carroll(redshift, cosmology)

Growth function.

This function returns the growth function as a function of redshift for a given cosmology as approximated by Carroll, Press & Turner (1992), equation 29 in [1].

Parameters

redshift(nz,) array_like

Array of redshifts at which to evaluate the growth function.

cosmologyastropy.cosmology.Cosmology

Cosmology object providing methods for the evolution history of omega_matter and omega_lambda with redshift.

Returns

growth(nz,) array_like

The growth function evaluated at the input redshifts for the given cosmology.

References

1

Carroll, M. and Press, W. and Turner, E., (1992), doi : 10.1146/annurev.aa.30.090192.002435

Examples

This example returns the growth function for a given array of redshifts and for the Astropy default cosmology:

>>> import numpy as np
>>> from astropy.cosmology import default_cosmology
>>> redshift = np.array([0, 1, 2])
>>> cosmology = default_cosmology.get()
>>> growth_function_carroll(redshift, cosmology)
array([0.781361..., 0.476280..., 0.327549...])