Public repository of the Cosmic Linear Anisotropy Solving System (master for the most recent version of the standard code; GW_CLASS to include Cosmic Gravitational Wave Background anisotropies; classnet branch for acceleration with neutral networks; ExoCLASS branch for exotic energy injection; class_matter branch for FFTlog)
For my work on the cross-correlation power spectrum, I am trying to validate the product of the matter power spectrum (at z = 0) and the growth factor (P(k,z=0)D(z)). I understand that using CLASSY, they can be calculated in two different ways using the relationship,
1) pk(k,z)/scale_independent_growth_factor(z)
2) pk(k,z=0)*scale_independent_growth_factor(z)
Using CLASSY, I tried to validate the equivalence of this relation (at z = 1) for the case of linear matter power spectrum (pk_lin) and the non-linear matter power spectrum (pk) [Note: I asked CLASSY for the nonlinear version using HaloFit]. However, the plots suggest that the relation holds for pk_lin and there is a clear difference when the non-linear power spectrum is used.
The comparison of the nonlinear matter power spectrum.
For my work on the cross-correlation power spectrum, I am trying to validate the product of the matter power spectrum (at z = 0) and the growth factor (P(k,z=0)D(z)). I understand that using CLASSY, they can be calculated in two different ways using the relationship,
1) pk(k,z)/scale_independent_growth_factor(z)
2) pk(k,z=0)*scale_independent_growth_factor(z)
Using CLASSY, I tried to validate the equivalence of this relation (at z = 1) for the case of linear matter power spectrum (pk_lin) and the non-linear matter power spectrum (pk) [Note: I asked CLASSY for the nonlinear version using HaloFit]. However, the plots suggest that the relation holds for pk_lin and there is a clear difference when the non-linear power spectrum is used.
The comparison of the nonlinear matter power spectrum.
Is there an obvious reason for this discrepancy?