Log-transforming the matter power spectrum

Understand

We investigate whether non-linear effects on the large-scale power spectrum of dark matter, namely the increase in small-scale power and the smearing of baryon acoustic oscillations, can be decreased by a log-transformation or emulated by an exponential transformation of the linear spectrum.

• To that end we present a formalism to convert the power spectrum of a log-normal field to the power spectrum of the logarithmic Gaussian field and vice versa.
• All ingredients of our derivation can already be found in various publications in cosmology and other fields.
• We follow a more pedagogical approach providing a detailed derivation, application examples, and a discussion of implementation subtleties in one text.