1. Oct 12, 2015

gluon

About the power spectrum: if increased the number of baryons the frequency of the oscillation reduced.I want to ask why this fact moves the power spectrum to higher multipoles and no to smaller?smaller frequency doesnt mean longer wavelength and thus smaller multipoles?

2. Oct 13, 2015

bapowell

Adding baryons also decreases the sound speed and so decreases the size of the sound horizon. Since the sound horizon sets the wavelength of the fundamental mode, the peaks shift to higher-\ell (or smaller wavelength).