The double copy: gravity from gluons

TL;DR

The paper reviews the double copy correspondence linking gravity and gauge theories, highlighting recent advances and potential applications in understanding quantum gravity and black holes.

Contribution

It summarizes recent developments in the double copy framework, establishing a connection between gravity and gauge theories for scattering amplitudes and other physical quantities.

Findings

Double copy relates gravity amplitudes to gauge theory amplitudes.

Extended to black hole analogues in gauge theories.

Potential applications in quantum gravity research.

Abstract

Three of the four fundamental forces in nature are described by so-called gauge theories, which include the effects of both relativity and quantum mechanics. Gravity, on the other hand, is described by General Relativity, and the lack of a well-behaved quantum theory - believed to be relevant at the centre of black holes, and at the Big Bang itself - remains a notorious unsolved problem. Recently a new correspondence, the double copy, has been discovered between scattering amplitudes (quantities related to the probability for particles to interact) in gravity, and their gauge theory counterparts. This has subsequently been extended to other quantities, providing gauge theory analogues of e.g. black holes. We here review current research on the double copy, and describe some possible applications.