No Slip CMB
  No Slip Gravity is a simple modified gravity theory with only one free
function and the interesting characteristic that -- unlike many modified
gravity theories -- it suppresses growth. This allows it to fit current
redshift space distortion and $\sigma_8$ mass fluctuation amplitude data better
than $\Lambda$CDM in general relativity, while retaining a $\Lambda$CDM
background expansion and hence distances. Since it has no gravitational slip it
alters equally CMB lensing and matter density growth, and in addition affects
the CMB gravitational wave B-mode polarization power spectrum. We investigate
and compute the effects of No Slip Gravity for CMB lensing and B-modes, and
present a simple analytic approximation. Using a Monte Carlo analysis, we place
constraints on the theory from current CMB data.
