(for Zoom link please email Silvia Nagy s.nagyATqmul.ac.uk There will be a pre-seminar for students at 13.30) ABSTRACT: A universal relationship between asymptotic symmetries, QFT soft theorems, and low energy observables has reinvigorated attempts at flat space holography. We will begin by introducing a map from 4d S-matrix elements to 2d correlators in a putative dual Celestial CFT, and then re-examine the IR triangle from the perspective of our Celestial CFT.