Perturbative interaction approach to cosmological structure formation

Understand

A new approach to cosmological perturbation theory has been recently introduced by Bartelmann et al., relying on nonequilibrium statistical theory of classical particles, and treating the gravitational interaction perturbatively.

• They compute analytic expressions for the nonlinear matter power spectrum, to first order in the interaction, and at one-loop order in the linear power spectrum.
• The resulting power spectrum is well behaved even at large wavenumbers and seems in good agreement with results from numerical simulations.
• In this paper, we rederive their results concisely with a different approach, starting from the implicit integral solution to particle trajectories.