| Nonlinear Effects in the Amplitude of Cosmological Density Fluctuations (2009) | |||||||||
Abstract | |||||||||
| The amplitude of cosmological density fluctuations, $\sigma_8$, has been studied and estimated by analysing many cosmological observations. The values of the estimates vary considerably between the various probes. However, different estimators probe the value of $\sigma_8$ in different cosmological scales and do not take into account the nonlinear evolution of the parameter at late times. We show that estimates of the amplitude of cosmological density fluctuations derived from cosmic flows are systematically higher than those inferred at early epochs because of nonlinear evolution at later times. Here we derive corrections to the value of $\sigma_8$ and compare amplitudes after accounting for this effect.. Comment: 9 pages, 1 figure, 1 table | |||||||||
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