CAMB: halofit matter power spectrum derivative
Posted: September 29 2017
Hey,
I was running a test involving python camb 0.1.6.1's Takahashi halofit matter power spectrum, and I notice that there is a large spike around kh=0.005 h Mpc^-1 in the second derivative of the matter power spectrum with respect to k, shown here:
I assume the spike itself is because the implementation of halofit switches to using the linear power spectrum for kh below Min_kh_nonlinear = 0.005, which creates a discontinuity, but I would not expect that to produce an extended feature like this, unless something is smoothing it out. Is camb applying a smoothing to the halofit output, or is this feature something else?
I was running a test involving python camb 0.1.6.1's Takahashi halofit matter power spectrum, and I notice that there is a large spike around kh=0.005 h Mpc^-1 in the second derivative of the matter power spectrum with respect to k, shown here:
I assume the spike itself is because the implementation of halofit switches to using the linear power spectrum for kh below Min_kh_nonlinear = 0.005, which creates a discontinuity, but I would not expect that to produce an extended feature like this, unless something is smoothing it out. Is camb applying a smoothing to the halofit output, or is this feature something else?