CMB Lensing Constraints on Dark Energy and Modified Gravity Scenarios

TL;DR

This paper explores how future CMB measurements can precisely constrain the lensing potential, thereby improving our understanding of dark energy and modified gravity theories, and highlights the importance of accurate lensing assumptions.

Contribution

It provides forecasts for constraining the integrated lensing potential from future CMB experiments and discusses implications for dark energy and modified gravity models.

Findings

Planck will constrain lensing amplitude to 6%

EPIC will constrain lensing amplitude to 1%

Incorrect assumptions on lensing amplitude can bias cosmological parameters

Abstract

Weak gravitational lensing leaves a characteristic imprint on the cosmic microwave background temperature and polarization angular power spectra. Here we investigate the possible constraints on the integrated lensing potential from future CMB angular spectra measurements expected from Planck and EPIC. We find that Planck and EPIC will constrain the amplitude of the integrated projected potential responsible for lensing at 6% and 1% level, respectively with very little sensitivity to the shape of the lensing potential. We discuss the implications of such a measurement in constraining dark energy and modified gravity scalar-tensor theories. We then discuss the impact of a wrong assumption on the weak lensing potential amplitude on cosmological parameter inference.