Doppler boosted dust emission and CIB-galaxy cross-correlations: a new probe of cosmology and astrophysics

Understand

We identify a new cosmological signal, the Doppler-boosted Cosmic Infrared Background (DB-CIB), arising from the peculiar motion of the galaxies whose thermal dust emission source the cosmic infrared background (CIB).

• This new observable is an independent probe of the cosmic velocity field, highly analogous to the well-known kinematic Sunyaev-Zel'dovich (kSZ) effect.
• Interestingly, DB-CIB does not suffer from the 'kSZ optical depth degeneracy', making it immune from the complex astrophysics of galaxy formation.
• We forecast that the DB-CIB effect is detectable in the cross-correlation of CCAT-Prime and DESI-like experiments.