Massive neutrinos and interacting dark matter look alike through the lens of lensing

Abstract

We demonstrate that the suppression in the lensing power spectrum of the cosmic microwave background (CMB) caused by massive neutrinos can be mimicked by dark matter-baryon interactions at the precision of next-generation CMB experiments. Thus, a determination of neutrino masses from the CMB lensing power spectrum may be compromised. We illustrate the degeneracy for a dark matter-proton cross section $\propto v^{-4}$, which arises in the $t$-channel exchange of an ultralight mediator in the nonrelativistic limit.

7 pages, 7 figures, 1 table. Version to appear in PRD

References in corpus (9)

• Ultralight scalars as cosmological dark matter
• Massive neutrinos and cosmology
• DESI DR2 Results II: Measurements of Baryon Acoustic Oscillations and Cosmological Constraints
• Milky Way Satellite Census. III. Constraints on Dark Matter Properties from Observations of Milky Way Satellite Galaxies
• KiDS-Legacy: Cosmological constraints from cosmic shear with the complete Kilo-Degree Survey
• Cosmological Constraints on Dark Matter Interactions with Ordinary Matter
• Neutrino cosmology after DESI: tightest mass upper limits, preference for the normal ordering, and tension with terrestrial observations
• Cosmological constraints on multi-interacting dark matter
• Sensitivity of the Global 21-cm Signal to Dark Matter-Baryon Scattering

Cited by in corpus (1)

• Breaking Free from the Swampland of Impossible Universes through the DESI Portal