Transverse Velocities with the Moving Lens Effect

Understand

Gravitational potentials which change in time induce fluctuations in the observed cosmic microwave background (CMB) temperature.

• Cosmological structure moving transverse to our line of sight provides a specific example known as the moving lens effect.
• Here we explore how the observed CMB temperature fluctuations combined with the observed matter over-density can be used to infer the transverse velocity of cosmological structure on large scales.
• We show that near-future CMB surveys and galaxy surveys will have the statistical power to make a first detection of the moving lens effect, and we discuss applications for the reconstructed transverse velocity.