sigma_r module

Compute anisotropy dispersion sigma(R,z)

Name: sigma_r

File: cosmosis-standard-library/boltzmann/sigmar/sigmar.py

Version: 1.0

Author(s):

Scott Dodelson

URL:

Cite:

Rules:

Assumptions:

minimal assumptions; sigma computed directly from P(k,z)

Explanation

sigma(R,z) is the variance of cosmic density fluctuations on scales
down to 8 Mpc/h.

In Fourier space is given by sigma(R,z) = \int_0^\infty W^2(k R) k^2 P(k,z) / (2 \pi)^2 dk

The P(k,z) used could in general be linear or non-linear, but usually when people
say sigma they mean the non-linear variant.

##Parameters

These parameters can be set in the module's section in the ini parameter file.
If no default is specified then the parameter is required.

Parameter	Description
zmin	real, minimum redshift to generate values for
zmax	real, maximum redshift to generate values for
dz	real, output redshift sample spacing
rmin	real, minimum scale R in Mpc/h to generate values for
rmax	real, maximum scale R in Mpc/h to generate values for
dr	real, scale R spacing
matter_power	name of section to get P(k,z) from, e.g. matter_power_lin, matter_power_nl
crop_klim	logical, crops the klimits of the sigma integral to max(0.01/R, kmin), min(100/R, kmax) (default T)

##Inputs

These parameters and data are inputs to the module, either supplied as parameters by the sampler or computed by some previous module. They are loaded from the data block.

Section	Parameter	Description
matter_power	k_h	real 1D array, sample values of linear spectrum in Mpc/h. Section name specified by parameter in ini file.
	z	real 1D array, redshift of linear spectrum samples. Section name specified by parameter in ini file.
	P_k	real 2D array, linear spectrum in (Mpc/h)^{-3}. Section name specified by parameter in ini file.

##Outputs

These parameters and data are computed as outputs from the module

Section	Parameter	Description
sigmar	R	real 1D array, scale R of output in Mpc/h
	z	real 1D array, redshift of output
	sigma2	real 2D array, variance sigma^2(R,z)

Wiki

cosmosis / default_modules / sigma_r_1.0

sigma_r module

Compute anisotropy dispersion sigma(R,z)