Presentation #326.02 in the session Gravitational Wave Cosmology and Methodologies.
Gravitational wave bursts with memory (BWMs) generate long-lived frequency shifts and permanent angular deflections in distant sources of light. The largest possible manifestation of this signal — a cumulative record of the GW history of the Universe — is in the most ancient light in the Universe: the cosmic microwave background (CMB). These perturbations vary across the sky with a characteristic spatial pattern and evolve slowly over cosmologically long periods of time. We demonstrate that a BWM can mix power from a spherical harmonic mode of a certain degree into modes of vastly different degree. In other words, BWM-induced perturbations to the CMB at any angular scale depend in detail on the unperturbed character of the CMB on all angular scales. Importantly, BWM-induced frequency shifts transfer power from the CMB monopole into higher order structure.