Flat-space Limit of AdS/CFT

Recent years have seen two major approaches to flat space holography: the codimension-2 Celestial Holography and the codimension-1 Carrollian Holography. In this talk, I will show how Carrollian Holography naturally emerges by taking the flat space limit of AdS/CFT, carefully tracking the null boundary direction. I will discuss how leading and sub-leading contributions in this limit arise from AdS Witten diagrams, and outline how the flat-space limit of loop diagrams relates to loop-level amplitudes in Carrollian field theory.