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 leftlangle VVmathcal{O}rightrangle maps to photon-photon-massive amplitudes.

Highlights

  • Including negative cosmological constant, gravity theory coupled to other local fields can be formulated as weakly coupled quantum field theory (QFT) by perturbatively expanding the curvatures around the Anti-de Sitter (AdS) background

  • We found that the scattering smearing kernel from Poincare AdS is a simple Fourier factor that brings the conformal field theory (CFT) correlator to momentum space

  • The scattering smearing kernel from global AdS is more nontrivial, and we found that it is served as the unified origin of other known frameworks of flat-space limit: Mellin space, coordinate space, and partial-waves

Read more

Summary

Introduction

Gravity theory coupled to other local fields can be formulated as weakly coupled quantum field theory (QFT) by perturbatively expanding the curvatures around the Anti-de Sitter (AdS) background. Only the scattering smearing kernel constructed from global AdS can be served as the origin of the flat-space limit in Mellin space, coordinate space, and partial-wave expansion; on the other hand, when we construct the scattering smearing kernel from Poincare AdS, we find it performs the Fourier-transform and gives rise to the framework of flat-space limit in momentum space. Using the saddle-points, we find a Mellin formula that applies to both massless scattering and massive scattering We show this Mellin formula gives rise to the flat-space limit in coordinate space, and to the partial-wave/phase-shift formula.

Global quantization and the flat-space limit
Poincare quantization and the momentum space
Known frameworks of the flat-space limit
Mellin space and saddle-points
Conformal frame subject to saddle-points
From Mellin space to coordinate space
All massless particles: bulk-point singularity
Include massive particles
From coordinate space to partial-waves
Massless phase-shift
Massive phase-shift
Momentum-coordinate duality
Fun with spinning flat-space limit
Conclusion
A Momentum space for Euclidean CFT
B Normalizing scattering smearing kernel
Global smearing
Poincare smearing
C Derivation of formulas in Mellin space
Limit of Mellin representation and massive formula
Derivation of massless formula
Findings
From Casimir equation

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.