The Imprint of f(R) Gravity on Non-Linear Structure Formation

We test the imprint of f® modified gravity on the halo mass function, using N-body simulations and a theoretical model developed in (Kopp et al. 2013). We find a very good agreement between theory and simulations. We extend the theoretical model to the conditional mass function and apply it to the prediction of the linear halo bias in f® gravity. Using the halo model we obtain a prediction for the non-linear matter power spectrum accurate to ~10% at z=0 and up to k=2h/Mpc. We also study halo profiles for the f® models and find a deviation from the standard general relativity result up to 40%, depending on the halo masses and redshift. This has not been pointed out in previous analysis. Finally we study the number density and profiles of voids identified in these f® N-body simulations. We underline the effect of the bias and the sampling to identify voids. We find significant deviation from GR when measuring the f® void profiles with fR0<-10^{-6}.