Quantum mechanics

Function (biology)

Algorithm

Scale (ratio)

Biology

Correlation function (quantum field theory)

Applied mathematics

Particle physics

Computation

Computer science

Numerical integration

Statistical physics

Evolutionary biology

Physics

Dielectric

Mathematics

Mathematical analysis

Numerical analysis

Quantum chromodynamics

Resummation

Journal of Cosmology and Astroparticle Physics

We develop an analytic method for implementing the IR-resummation of arXiv:1404.5954, which allows one to correctly and consistently describe the imprint of baryon acoustic oscillations (BAO) on statistical observables in large-scale structure. We show that the final IR-resummed correlation function can be computed analytically without relying on numerical integration, thus allowing for an efficient and accurate use of these predictions on real data in cosmological parameter fitting. In this work we focus on the one-loop correlation function and the BAO peak. We show that, compared with the standard numerical integration method of IR-resummation, the new method is accurate to better than 0.2 %, and is quite easily improvable. We also give an approximate resummation scheme which is based on using the linear displacements of a fixed fiducial cosmology, which when combined with the method described above, is about six times faster than the standard numerical integration. Finally, we show that this analytic method is generalizable to higher loop computations.

An analytic implementation of the IR-resummation for the BAO peak