Time-Sliced Perturbation Theory II: Baryon Acoustic Oscillations and Infrared Resummation

Understand

We use time-sliced perturbation theory (TSPT) to give an accurate description of the infrared non-linear effects affecting the baryonic acoustic oscillations (BAO) present in the distribution of matter at very large scales.

• In TSPT this can be done via a systematic resummation that has a simple diagrammatic representation and does not involve uncontrollable approximations.
• We discuss the power counting rules and derive explicit expressions for the resummed matter power spectrum up to next-to leading order and the bispectrum at the leading order.
• The two-point correlation function agrees well with N-body data at BAO scales.