Cross-correlations: NumCosmo Reference Manual

Cross-correlations

Cross-correlations — Angular auto- and cross-spectra.

Functions

NcXcor *	nc_xcor_new ()
NcXcor *	nc_xcor_ref ()
void	nc_xcor_free ()
void	nc_xcor_clear ()
void	nc_xcor_prepare ()
void	nc_xcor_limber ()

Properties

NcDistance *	distance	Read / Write / Construct Only
NcXcorLimberMethod	meth	Read / Write / Construct
NcmPowspec *	power-spec	Read / Write / Construct Only

Types and Values

enum	NcXcorLimberMethod
#define	NC_XCOR_PRECISION

Object Hierarchy

    GEnum
    ╰── NcXcorLimberMethod
    GObject
    ╰── NcXcor

Description

The angular power spectrum between observables $A$ and $B$ with kernels $W^A$ and $W^B$ is \begin{equation} C_{\ell}^{AB} &= \int dz W^A(z) \int dz^\prime W^B (z^\prime) \times \int dk \frac{2}{\pi} k^2 P(k, z, z^\prime) j_{\ell}(k\chi(z)) j_{\ell} (k\chi(z^\prime)). \end{equation} In the Limber approximation, it reduces to \begin{equation} C_{\ell}^{AB} = \int_0^{z_*} dz \frac{H(z)}{c \chi^2(z)} W^A(z) W^B (z) P\left(k = \frac{\ell +1/2}{\chi(z)} , z \right), \end{equation} where $P\left(k = \frac{\ell +1/2}{\chi(z)} , z \right)$ is the power spectrum (a NcmPowspec) at redshift $z$ and $chi(z)$ the comoving distance (a NcDistance).

Functions

nc_xcor_new ()

NcXcor *
nc_xcor_new (NcDistance *dist,
             NcmPowspec *ps,
             NcXcorLimberMethod meth);

Two methods are available to compute Limber-approximated integrals: independent GSL numerical integration or vector integration using Sundials's CVode algorithm.

Parameters

dist	a NcDistance
ps	a NcmPowspec
meth	a NcXcorLimberMethod to compute the Limber integrals

Returns

FIXME

nc_xcor_ref ()

NcXcor *
nc_xcor_ref (NcXcor *xc);

Parameters

a NcXcor

Returns

xc .

[transfer full]

nc_xcor_free ()

void
nc_xcor_free (NcXcor *xc);

FIXME

Parameters

a NcXcor

nc_xcor_clear ()

void
nc_xcor_clear (NcXcor **xc);

FIXME

Parameters

a NcXcor

nc_xcor_prepare ()

void
nc_xcor_prepare (NcXcor *xc,
                 NcHICosmo *cosmo);

FIXME

Parameters

xc	a NcXcor
cosmo	a NcHICosmo

nc_xcor_limber ()

void
nc_xcor_limber (NcXcor *xc,
                NcXcorLimberKernel *xclk1,
                NcXcorLimberKernel *xclk2,
                NcHICosmo *cosmo,
                guint lmin,
                guint lmax,
                NcmVector *vp);

Performs the computation of the power spectrum $C_{\ell}^{AB}$ in the Limber approximation. The kernels of observables A and B are xclk1 and xclk2 . If xclk2 is NULL, the auto power spectrum is computed. The result for multipoles lmin to lmax (included) is stored in the NcmVector vp .

Parameters

xc	a NcXcor
xclk1	a NcXcorLimberKernel
xclk2	a NcXcorLimberKernel
cosmo	a NcHICosmo
lmin	a guint
lmax	a guint
vp	a NcmVector

Types and Values

enum NcXcorLimberMethod

FIXME

Members

NC_XCOR_LIMBER_METHOD_GSL	FIXME
NC_XCOR_LIMBER_METHOD_CVODE	FIXME
NC_XCOR_LIMBER_METHOD_SUAVE	FIXME

NC_XCOR_PRECISION

#define NC_XCOR_PRECISION (1e-5)

Property Details

The `“distance”` property

  “distance”                 NcDistance *

This property keeps the distance object.

Owner: NcXcor

Flags: Read / Write / Construct Only

The `“meth”` property

  “meth”                     NcXcorLimberMethod

This property keeps the method enumerator to compute the integrals.

Owner: NcXcor

Flags: Read / Write / Construct

Default value: NC_XCOR_LIMBER_METHOD_GSL

The `“power-spec”` property

  “power-spec”               NcmPowspec *

This property keeps the matter power spectrum object.

Owner: NcXcor

Flags: Read / Write / Construct Only