CMB Lensing and Scale Dependent New Physics

TL;DR

This paper explores how cosmic microwave background lensing can detect scale-dependent new physics like modified gravity, neutrino mass, and dark energy, emphasizing the importance of high-resolution polarization experiments.

Contribution

It analyzes the signatures of scale-dependent physics on CMB lensing and discusses how different redshift weightings can help distinguish these effects.

Findings

CMB lensing can probe diverse physics including modified gravity and neutrino mass.

Arcminute resolution polarization experiments are crucial for distinguishing physical effects.

Scale dependence in new physics leaves unique signatures on CMB lensing signals.

Abstract

Cosmic microwave background lensing has become a new cosmological probe, carrying rich information on the matter power spectrum and distances over the redshift range $z\approx1$-4. We investigate the role of scale dependent new physics, such as from modified gravity, neutrino mass, and cold (low sound speed) dark energy, and its signature on CMB lensing. The distinction between different scale dependences, and the different redshift dependent weighting of the matter power spectrum entering into CMB lensing and other power spectra, imply that CMB lensing can probe simultaneously a diverse range of physics. We highlight the role of arcminute resolution polarization experiments for distinguishing between physical effects.