Nov 1, 2018 - Check kappa power spectra

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As a sanity check we compare power spectra of the kappa maps from George's sims against theoretical expectations from CAMB. The dictionary between the two languages is

[math]\displaystyle{ \phi_{\ell m} = \frac{2\kappa_{\ell m}}{\ell(\ell+1)} }[/math]

The CAMBdemo code from https://camb.readthedocs.io/en/latest/CAMBdemo.html contains an analytic code based on Limber approximation to calculate power spectrum of the CMB lensing potential. We slightly modify it to be applicable to our case of a general comoving distance. In the plots below we compare power spectra from the Peak Patch simulations against analytic expectation based on (non)linear matter power spectrum. Just for a quick check we also plot CMB lensing potential power spectrum, both from full CAMB and from the analytic expectation.

Pavel 03 camb comparison zs 4200 Mpc.png Pavel 03 camb comparison zs 6200 Mpc.png Pavel 03 camb comparison zs 8200 Mpc.png