Time: 09:30 am (UTC/GMT+08:00, Beijing/Shanghai), Aug. 18 (Tues.), 2020

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Meeting ID: 913 4672 6097

Speaker: Xinan Zhou (IAS, Princeton)

Abstract:

Correlation functions are the most basic observables of CFTs, and are mapped to AdS scattering amplitudes via AdS/CFT. However, a brute force computation is notoriously difficult and has led to only a handful of results in the past 20 years. Only recently we begin to discover and appreciate the hidden structures and simplicities of these curved space amplitudes, which in many ways are reminiscent of their flat space counterparts. The goal of this talk is to give an overview of the current status of this program and introduce the modern methods. In particular, I will introduce a powerful new method that gives a closed form answer for all tree-level four-point amplitudes in theories with maximally supersymmetry. This includes IIB SUGRA on AdS5xS5 (dual to 4d N=4 SYM), and 11D SUGRA on AdS4xS7 and AdS7xS4 (respectively dual to 3d N=8 ABJM and 6d (2,0) theory). An important ingredient of this new method is the notion of maximally R-symmetry violating (MRV) amplitude. In this limit amplitudes drastically simplify and become easy to compute. I will then explain how the full amplitudes can be recovered from this limit by using symmetries, and present the general results for these theories. Along the way, I will highlight close analogies with the flat space scattering amplitudes. I will also make brief comments on various exciting extensions of this program in the future.

The talk is based on 2006. 12505 and 2006.06653, see also 1608. 06624, 1710.05923, 1712.02788, 1712.02800 for earlier developments.