String Theory Journal Club

I will discuss recent advances in Carroll limits of field theories and their relation to celestial holography. Motivated by asymptotic symmetries and their relation to soft photons, celestial holography maps four-dimensional scattering amplitudes to correlators in a two-dimensional CFT. However, such celestial CFTs have several nonstandard features, and only few explicit examples are known. On the other hand, one can consider flat space limits of AdS/CFT which naturally lead to three-dimensional CFTs with Carroll symmetry. After reviewing some of the recent progress on applications of non-Lorentzian geometry in limits and expansions of Lorentzian theories such as general relativity and string theory, I will introduce a related geometric method for constructing Carroll CFTs from a limit of Lorentzian CFTs, and I will discuss their relation to celestial CFTs. Zoom link: https://uw-edu-pl.zoom.us/j/94454442398