We use an ensemble of N-body simulations of the currently favoured ( concordance ) cosmological model to measure the amount of information contained in the non-linear matter power spectrum about the amplitude of the initial power spectrum .
Two surprising results emerge from this study : ( i ) that there is very little independent information in the power spectrum in the translinear regime ( k \simeq 0.2 –0.8 h Mpc ^ { -1 } at the present day ) over and above the information at linear scales and ( ii ) that the cumulative information begins to rise sharply again with increasing wavenumber in the non-linear regime .
In the fully non-linear regime , the simulations are consistent with no loss of information during translinear and non-linear evolution .
If this is indeed the case then the results suggest a picture in which translinear collapse is very rapid , and is followed by a bounce prior to virialization , impelling a wholesale revision of the HKLM-PD formalism .