pyccl.halos.profiles_2pt module

class pyccl.halos.profiles_2pt.Profile2pt(self, *, r_corr=0.0)[source]

Bases: CCLAutoRepr

This class implements the 1-halo 2-point correlator between two halo profiles.

\[\langle u_1(k) u_2(k) \rangle.\]

In the simplest case the second-order cumulant is just the product of the individual Fourier-space profiles. More complicated cases are implemented via the parameters of this class.

Parameters:

r_corr (float) – Tuning knob for the 1-halo 2-point correlation. Scale the correlation by \((1+\rho_{u_1, u_2})\). This is useful when the individual 1-halo terms are not fully correlated. Example usecases can be found in arXiv:1909.09102 and arXiv:2102.07701. Defaults to r_corr=0, returning simply the product of the fourier profiles.

update_parameters(*, r_corr=None)[source]

Update any of the parameters associated with this 1-halo 2-point correlator. Any parameter set to None won’t be updated.

fourier_2pt(cosmo, k, M, a, prof, *, prof2=None, diag=True)[source]

Return the Fourier-space two-point moment between two profiles.

\[(1+\rho_{u_1,u_2})\langle u_1(k)\rangle\langle u_2(k) \rangle\]
Parameters:

  • cosmo (Cosmology) – a Cosmology object.

  • k (float or array) – comoving wavenumber in Mpc^-1.

  • M (float or array) – halo mass in units of M_sun.

  • a (float) – scale factor.

  • prof (HaloProfile) – halo profile for which the second-order moment is desired.

  • prof2 (HaloProfile) – second halo profile for which the second-order moment is desired. If None, the assumption is that you want an auto-correlation, and prof will be used as prof2.

  • diag (bool) – If True, both halo profiles depend on the same k. If

  • False –

  • k' (they will depend on k and) –

  • output (respectively. The) –

  • ` (dimension will change to) –

Returns:

second-order Fourier-space moment. The shape of the output will be (N_M, N_k) where N_k and N_m are the sizes of k and M respectively, if diag is True. If False, the array will have dimension (N_M, N_k, N_k), with k’ corresponding to the second axis of the array.. If k or M are scalars, the corresponding dimension will be squeezed out on output.

Return type:

(float or array)

class pyccl.halos.profiles_2pt.Profile2ptHOD(self, *, r_corr=0.0)[source]

Bases: Profile2pt

This class implements the Fourier-space 1-halo 2-point correlator for the HOD profile.

\[\langle n_g^2(k)|M,a\rangle = \bar{N}_c(M,a) \left[2f_c(a)\bar{N}_s(M,a) u_{\rm sat}(r|M,a)+ (\bar{N}_s(M,a) u_{\rm sat}(r|M,a))^2\right],\]

where all quantities are described in the documentation of HaloProfileHOD.

fourier_2pt(cosmo, k, M, a, prof, *, prof2=None, diag=True)[source]

Returns the Fourier-space two-point moment for the HOD profile.

Parameters:

  • cosmo (Cosmology) – a Cosmology object.

  • k (float or array) – comoving wavenumber in Mpc^-1.

  • M (float or array) – halo mass in units of M_sun.

  • a (float) – scale factor.

  • prof (HaloProfileHOD) – halo profile for which the second-order moment is desired.

  • prof2 (HaloProfileHOD or None) – second halo profile for which the second-order moment is desired. If None, the assumption is that you want an auto-correlation. Note that only auto-correlations are allowed in this case.

  • diag (bool) – If True, both halo profiles depend on the same k. If False, they will depend on k and k’, respectively and we will approximate <uk uk’> to <uk><uk’>. The output dimension will change to (N_M, N_k, N_k). Default True.

Returns:

second-order Fourier-space moment. The shape of the output will be (N_M, N_k) where N_k and N_m are the sizes of k and M respectively, if diag is True. If False, the array will have dimension (N_M, N_k, N_k), with k’ corresponding to the second axis of the array.. If k or M are scalars, the corresponding dimension will be squeezed out on output.

Return type:

(float or array)

class pyccl.halos.profiles_2pt.Profile2ptCIB(self, *, r_corr=0.0)[source]

Bases: Profile2pt

This class implements the Fourier-space 1-halo 2-point correlator for the CIB profile. It follows closely the implementation of the equivalent HOD quantity (see Profile2ptHOD and Eq. 15 of McCarthy & Madhavacheril).

fourier_2pt(cosmo, k, M, a, prof, *, prof2=None, diag=True)[source]

Returns the Fourier-space two-point moment for the CIB profile.

Parameters:

  • cosmo (Cosmology) – a Cosmology object.

  • k (float or array) – comoving wavenumber in Mpc^-1.

  • M (float or array) – halo mass in units of M_sun.

  • a (float) – scale factor.

  • prof (HaloProfileCIBShang12) – halo profile for which the second-order moment is desired.

  • prof2 (HaloProfileCIBShang12) – second halo profile for which the second-order moment is desired. If None, the assumption is that you want an auto-correlation. Note that only auto-correlations are allowed in this case.

  • diag (bool) – If True, both halo profiles depend on the same k. If False, they will depend on k and k’, respectively and we will approximate <uk uk’> to <uk><uk’>. The output dimension will change to (N_M, N_k, N_k). Default True.

Returns:

second-order Fourier-space moment. The shape of the output will be (N_M, N_k) where N_k and N_m are the sizes of k and M respectively, if diag is True. If False, the array will have dimension (N_M, N_k, N_k), with k’ corresponding to the second axis of the array. If k or M are scalars, the corresponding dimension will be squeezed out on output.

Return type:

(float or array)