Superhorizon Perturbations and the Cosmic Microwave Background

Erickcek, Adrienne L.; Carroll, Sean M.; Kamionkowski, Marc

Superhorizon Perturbations and the Cosmic Microwave Background

Authors

Erickcek, Adrienne L.

Carroll, Sean M.

Kamionkowski, Marc

Description

Superhorizon perturbations induce large-scale temperature anisotropies in the cosmic microwave background (CMB) via the Grishchuk-Zel'dovich effect. We analyze the CMB temperature anisotropies generated by a single-mode adiabatic superhorizon perturbation. We show that an adiabatic superhorizon perturbation in a LCDM universe does not generate a CMB temperature dipole, and we derive constraints to the amplitude and wavelength of a superhorizon potential perturbation from measurements of the CMB quadrupole and octupole. We also consider constraints to a superhorizon fluctuation in the curvaton field, which was recently proposed as a source of the hemispherical power asymmetry in the CMB.
11 pages, 4 figures, submitted to PRD