# Flat space physics from AdS/CFT

## TL;DR

This paper introduces a formula linking scattering amplitudes to conformal field theory correlators, enabling a microscopic understanding of flat space gravitational theories via AdS/CFT correspondence.

## Contribution

It provides a novel flat limit approach in AdS/CFT, connecting scattering amplitudes with CFT correlators for both massive and massless particles.

## Key findings

- Validates the formula in (2+1)-dimensional examples
- Reproduces known scattering results in flat geometries
- Extends existing literature to include massive particles

## Abstract

We propose a formula relating scattering S-matrix amplitudes to correlators of a conformal field theory. The proposal implements a flat limit of the field theory, providing an indirect microscopic description of gravitational theories with asymptotically flat boundary conditions. The formula is valid for both massive and massless external particles, and reduces to existing expressions in the literature when all particles are either simultaneously massless or massive. We test the result in various (2+1)-dimensional examples such as simple BMS3 invariant correlators and blocks. We also study two-point correlators in conformal field theory deficit states to obtain known expressions for non-trivial scattering in asymptotically flat conical geometries.