Speaker
Description
The tight constraints on the $\mu$ type distortions in the CMB blackbody spectrum coming from the FIRAS observations can be used to set up the bounds on primordial curvature perturbations and thus on the Primordial Black Holes (PBHs). To do so, the conventional works assume the Gaussian initial conditions. However, it is well known that the enhancement in the primordial power spectrum needed to seed the PBH formation could lead to highly non-Gaussian statistics, hence, questioning such an assumption of Gaussianity. We shed light on this issue by providing a semi-analytic calculation of the spectral distortions in the presence of a local type non-Gaussianity, in perturbative and strong non-perturbative limits, in addition to a thorough comparison of the standard approximation schemes for the distortion source functions. Moreover, we also discuss a full calculation of PBH constraints on top of reassessing the question of PBHs as the seeds of SMBHs. This talk will be inspired by two articles in collaboration with J. Lesgourgues and C. Byrnes that will be published before this conference.
