Testing inflation on all scales: CMB, PBHs and Gravitational Waves

by Michael Bacchi (Universidade Federal do Espírito Santo)

Thursday 25 Sept 2025, 11:00 → 13:00 Europe/Rome

When searching for viable inflationary models, one should identify good models by their ability to simultaneously explain current observations on all scales. In this presentation, I will show the importance to constrain the parameter space by comparing the large-scale predictions for the power spectrum with current CMB anisotropies measurements and upper limits on μ-distortions, while at the same time take into account uncertainties due to the reheating phase. Moving to smaller scales, we compute the Non-Gaussianity at peak scale and the abundance of PBHs, further restraining the viable region of the parameter space that does not over-produce them. Finally, by calculating the signal-to-noise ratio for different gravitational waves experiments and comparing it with the astrophysical foregrounds, we select the best suited experiment to test the inflationary model in the future. While this study was performed for the hybrid α-attractors case, this approach, that combines tests at different scales, and exploits the synergy between cosmological observations and theoretical consistency requirements, could be applied to any other inflationary model and can be used to establish the small-scale phenomenology of inflationary models on firm grounds