skypy.power_spectrum.halofit_takahashi

skypy.power_spectrum.halofit_takahashi(wavenumber, redshift, linear_power_spectrum, cosmology, *, parameters=HalofitParameters(a=[0.225, 0.9903, 2.3706, 2.8553, 1.5222, - 0.6038, 0.1749], b=[0.5716, 0.5864, - 0.5642, - 1.5474, 0.2279], c=[0.8161, 2.0404, 0.3698, 0.5869], gamma=[- 0.0843, 0.1971, 0.846], alpha=[- 0.1959, 1.3373, 6.0835, - 5.5274], beta=[0.398, 1.249, 0.3157, - 0.7354, 2.0379, - 0.1682], mu=[0.0, - inf], nu=[3.6902, 5.2105], fa=[- 0.0732, - 0.1423, 0.0725], fb=[- 0.0307, - 0.0585, 0.0743], l=0.0, m=0.0, p=0.0, r=0.0, s=0.0, t=0.0))

Computation of the non-linear halo power spectrum.

This function computes the non-linear halo power spectrum, as a function of redshift and wavenumbers, following [1], [2] and [3].

Parameters

k(nk,) array_like

Input wavenumbers in units of Mpc-1.

z(nz,) array_like

Input redshifts

P(nz, nk) array_like

Linear power spectrum for given wavenumbers and redshifts Mpc3.

cosmologyastropy.cosmology.Cosmology

Cosmology object providing method for the evolution of omega_matter with redshift.

parametersHalofitParameters

namedtuple containing the free parameters of the model.

Returns

pknl(nz, nk) array_like

Non-linear halo power spectrum in units of Mpc3.

References

1

R. E. Smith it et al., VIRGO Consortium, Mon. Not. Roy. Astron. Soc. 341, 1311 (2003).

2

R. Takahashi, M. Sato, T. Nishimichi, A. Taruya and M. Oguri, Astrophys. J. 761, 152 (2012).

3

S. Bird, M. Viel and M. G. Haehnelt, Mon. Not. Roy. Astron. Soc. 420, 2551 (2012).

Examples

>>> import numpy as np
>>> from astropy.cosmology import default_cosmology
>>> from skypy.power_spectrum import growth_function, eisenstein_hu, halofit_smith
>>> k = np.logspace(-4, 2, 100, base=10)
>>> z, A_s, n_s = 0, 2.2e-09, 0.97
>>> cosmology = default_cosmology.get()
>>> dz = growth_function(z, cosmology)
>>> linear_power = eisenstein_hu(k, A_s, n_s, cosmology) * np.square(dz)
>>> nonlinear_power = halofit_smith(k, z, linear_power, cosmology)