High Energy Theory Seminar

In this talk, I will present a simple chiral 2d Lagrangian living on a 2d celestial sphere on the null boundary of 4d Minkowski space and briefly mention its first principal derivation using twistor theory. The behaviour of the 2d theory exactly produces various IR dynamics of recent resurged interests for 4d self-dual Einstein gravity in Minkowski space. I shall demonstrate how to use simple 2d CFT computations to reproduce 4d BMS generators and the $w_{1+\infty}$ algebra, deduce the explicit form of stress tensors and recover the necessity for dressing hard particles asymptotically with soft modes. I also further discuss how possible extensions of this 2d theory incorporates further tree level observables of 4d Einstein gravity such as form factors. If time permits, I'll further discuss partition function computations for these large diffeomorphism modes around both vacuum and self-dual Taub-NUT, their quotient exhibits non-trivial information about 4d Einstein gravity.

The talk is in 469 Lauritsen.

Contact [email protected] for Zoom information.