Bias

One of the most important ingredients of the Galaxy Clustering Weight function is the Galaxy Bias, that is, the statistical relation between the distribution of galaxies and matter

\[\delta_{g}(\boldsymbol{x})=b \delta(\boldsymbol{x})\]

In this page are listed the Bias Model we have implemented.

PiecewiseBias

The Piecewise Bias model is taken from the official Euclid forecast

\[b(z)= \sqrt{1+\bar{z}}\]

where $\bar{z}$ is the redshift value in the center of the tomographic bin where the redshift $z$ lies. The PiecewiseBias here is plotted.

CosmologicalGrid = CosmoCentral.CosmologicalGridStruct(
        ZArray = LinRange(0.001, 2.5, 500))
ConvolvedDensity = CosmoCentral.ConvolvedDensityStruct(DensityGridArray =
        ones(10, length(CosmologicalGrid.ZArray)))
GCWeightFunction = CosmoCentral.GCWeightFunctionStruct(WeightFunctionArray=
        zeros(length(ConvolvedDensity.DensityGridArray[1,:]),
        length(CosmologicalGrid.ZArray)))
CosmoCentral.ComputeBiasOverGrid(CosmologicalGrid, GCWeightFunction,
GCWeightFunction.BiasKind,
ConvolvedDensity)
x = CosmologicalGrid.ZArray; y = GCWeightFunction.BiasArray[1, :];
plot(x, y, label = "Bias", xlabel="z")

CosmoCentral.ComputeBias — Function

ComputeBias(z::Float64, ::PiecewiseBiasStruct,
ConvolvedDensity::AsbtractConvolvedDensity)

This function evaluate the piecewise bias, given by $\sqrt{1+z}$, for a given redshift.

source

CosmoCentral.ComputeBiasOverGrid — Function

ComputeBiasOverGrid(CosmologicalGrid::CosmologicalGrid,
GCWeightFunction::GCWeightFunctionStruct, Bias::AbstractBias,
ConvolvedDensity::AsbtractConvolvedDensity)

This function evaluate the bias, over the cosmological redshift grid.

source