Notes on flat-space limit of AdS/CFT

• Main Author: Yue-Zhou Li
• Format: Article
• Language: English
• Published: SpringerOpen 2021-09-01
• Series: Journal of High Energy Physics
• Subjects: AdS-CFT Correspondence; Conformal Field Theory
• Online Access: https://doi.org/10.1007/JHEP09(2021)027

Abstract Different frameworks exist to describe the flat-space limit of AdS/CFT, include momentum space, Mellin space, coordinate space, and partial-wave expansion. We explain the origin of momentum space as the smearing kernel in Poincare AdS, while the origin of latter three is the smearing kernel in global AdS. In Mellin space, we find a Mellin formula that unifies massless and massive flat-space limit, which can be transformed to coordinate space and partial-wave expansion. Furthermore, we also manage to transform momentum space to smearing kernel in global AdS, connecting all existed frameworks. Finally, we go beyond scalar and verify that VV O $$ \left\langle VV\mathcal{O}\right\rangle $$ maps to photon-photon-massive amplitudes.