dsf.data_vector.profiles module¶

Power-spectrum-backed density profiles for Delta Sigma.

This module builds generic CCL Pk2D objects that represent density-weighted matter power spectra. These objects can be passed to HaloProfileGeneric so that CCL’s projected-profile machinery can be reused to compute Delta Sigma profiles.

The returned profiles are not halo-mass-dependent halo profiles. They are Fourier-space density profiles constructed from

rho_m(a) * P_mm(k, a),

where rho_m is the comoving mean matter density and P_mm is either the linear or nonlinear matter power spectrum.

dsf.data_vector.profiles.density_weighted_power_spectrum(cosmo, power_spectrum)[source]¶

Build a density-weighted matter power spectrum.

This converts a CCL matter power spectrum function into a Pk2D object representing

\[\rho_\mathrm{m}(a) P_\mathrm{mm}(k, a).\]

The density weighting is needed because the generic Delta Sigma profile uses the supplied Pk2D as a Fourier-space density profile rather than as a dimensionless halo profile.

Parameters:

cosmo (Cosmology) – CCL cosmology object.
power_spectrum (Callable[[Cosmology, ndarray[tuple[Any, ...], dtype[float64]], float], ndarray[tuple[Any, ...], dtype[float64]]]) – Function with signature power_spectrum(cosmo, k, a) returning the matter power spectrum evaluated at wavenumber k and scale factor a.

Returns:

CCL Pk2D object for the density-weighted matter power spectrum.

Return type:

Pk2D

dsf.data_vector.profiles.linear_twohalo_density_profile(cosmo)[source]¶

Return the density-weighted linear two-halo profile.

This builds a Pk2D object proportional to

\[\rho_\mathrm{m}(a) P_\mathrm{lin}(k, a),\]

which can be used by HaloProfileGeneric as the Fourier-space profile for a linear two-halo Delta Sigma calculation.

Parameters:: cosmo (Cosmology) – CCL cosmology object.
Returns:: Density-weighted linear matter power spectrum as a CCL Pk2D object.
Return type:: Pk2D

dsf.data_vector.profiles.nonlinear_twohalo_density_profile(cosmo)[source]¶

Return the density-weighted nonlinear two-halo profile.

This builds a Pk2D object proportional to

\[\rho_\mathrm{m}(a) P_\mathrm{nl}(k, a),\]

which can be used by HaloProfileGeneric as the Fourier-space profile for a nonlinear two-halo Delta Sigma calculation.

Parameters:: cosmo (Cosmology) – CCL cosmology object.
Returns:: Density-weighted nonlinear matter power spectrum as a CCL Pk2D object.
Return type:: Pk2D