Effect of Hot Baryons on the Weak-Lensing Shear Power Spectrum
  We investigate the impact of the intracluster medium on the weak-lensing shear power spectrum (PS). Using a halo model we find that, compared to the dark matter only case, baryonic pressure leads to a suppression of the shear PS on the order of a few percent or more for $l \gtrsim 1000$. Cooling/cooled baryons and the intergalactic medium can further alter the shear PS. Therefore, the interpretation of future precision weak lensing data at high multipoles must take into account the effects of baryons. 
Hu Zhan, Lloyd Knox (UC Davis)