Multimessenger Cosmology: correlating CMB and SGWB measurements. (arXiv:2004.06619v2 [astro-ph.CO] UPDATED)

Multimessenger Cosmology: correlating CMB and SGWB measurements. (arXiv:2004.06619v2 [astro-ph.CO] UPDATED)
<a href="http://arxiv.org/find/astro-ph/1/au:+Adshead_P/0/1/0/all/0/1">Peter Adshead</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Afshordi_N/0/1/0/all/0/1">Niayesh Afshordi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Dimastrogiovanni_E/0/1/0/all/0/1">Emanuela Dimastrogiovanni</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Fasiello_M/0/1/0/all/0/1">Matteo Fasiello</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lim_E/0/1/0/all/0/1">Eugene A. Lim</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Tasinato_G/0/1/0/all/0/1">Gianmassimo Tasinato</a>

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). We show that, for inflationary models that
generate suitably large STT non-Gaussianities, cross-correlating the CMB with
the stochastic background of gravitational waves is a very effective probe of
early universe physics. The resulting signal can be a smoking-gun for
primordial SGWB anisotropies.

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). We show that, for inflationary models that
generate suitably large STT non-Gaussianities, cross-correlating the CMB with
the stochastic background of gravitational waves is a very effective probe of
early universe physics. The resulting signal can be a smoking-gun for
primordial SGWB anisotropies.

http://arxiv.org/icons/sfx.gif