Multimessenger Cosmology: correlating CMB and SGWB measurements

Understand

Characterizing the physical properties of the stochastic gravitational waves background (SGWB) is a key step towards identifying the nature of its possible origin.

• We focus our analysis on SGWB anisotropies.
• The existence of a non-trivial primordial scalar-tensor-tensor (STT) correlation in the squeezed configuration may be inferred from the effect that a long wavelength scalar mode has on the gravitational wave power spectrum: an anisotropic contribution.
• Crucially, such contribution is correlated with temperature anisotropies in the cosmic microwave background (CMB).