Just enough inflation: power spectrum modifications at large scales

Persistent hints in multiple datasets point towards a lack of CMB power on large angular scales. Motivated by this fact I will show how a pre-inflationary phase followed by a short period of slow roll inflation can help explain such lack of CMB power. I will present a systematic analysis of all possible pre-inflationary backgrounds and how these affect the power on the largest scales, highlighting the surprisingly high degree of degeneracy found.