Double copy theory explained

Double copy theory is a theory in theoretical physics, specifically in quantum gravity, that hypothesizes a perturbative duality between gauge theory and gravity. The theory says that scattering amplitudes in non-Abelian gauge theories can be factorized such that replacement of the color factor by additional kinematic dependence factor, in a well-defined way, automatically leads to gravity scattering amplitudes. It was first written down by Zvi Bern, John Joseph Carrasco and Henrik Johansson in 2010 ^[1] and was sometimes known as the BCJ duality after its creators^[2] or as "gravity = gauge × gauge".^[3]

The theory can be used to make calculations of gravity scattering amplitudes simpler by instead calculating the Yang–Mills amplitude and following the double copy prescription.^[4] This technique has been used, for example, to calculate the shape of gravitational waves emitted by two merging black hole.^{[5] [6]} This was proven to work at tree level and at higher orders,^[1] including at fourth post-Minkowskian order.^[7] The theory has been applied to black holes.^[8]

See also

• Duality
• Yang–Mills theory
• N = 8 supergravity

External links

• Web site: Wood . Charlie . How Gravity Is a Double Copy of Other Forces . Quanta Magazine . 2021-05-04 . none . 2021-05-09.
• Web site: KLT relations . nLab . none.

Notes and References

1. 1004.0476 . Perturbative Quantum Gravity as a Double Copy of Gauge Theory. Physical Review Letters. 105. 6. Bern. Zvi. Carrasco. John Joseph M. Johansson. Henrik. 2010. 061602. 10.1103/PhysRevLett.105.061602. 20867971. 2010PhRvL.105f1602B. 35590493.
2. Oxburgh, S. and White, C.D. . BCJ duality and the double copy in the soft limit. . J. High Energy Phys. . 22 February 2013 . 2013 . 127 . 127 . 10.1007/JHEP02(2013)127 . 1210.1110 . 2013JHEP...02..127O . 119175289 .
3. Borsten . L. . Gravity as the square of gauge theory: a review . La Rivista del Nuovo Cimento . 11 March 2020 . 43 . 3 . 97–186 . 10.1007/s40766-020-00003-6 . 2020NCimR..43...97B . 216347827 .
4. White . C. D. . The double copy: gravity from gluons . Contemporary Physics . 12 January 2018 . 59 . 2 . 109–125 . 10.1080/00107514.2017.1415725 . 1708.07056 . 2018ConPh..59..109W . 118863994 .
5. Goldberger . Walter D. . Ridgway . Alexander K. . 2017-06-30 . Radiation and the classical double copy for color charges . Physical Review D . 95 . 12 . 125010 . 10.1103/PhysRevD.95.125010. 1611.03493 . 2017PhRvD..95l5010G . 22057355 .
6. Web site: Wood . Charlie . 2022-03-29 . Massive Black Holes Shown to Act Like Quantum Particles . 2022-04-06 . Quanta Magazine . en.
7. Bern. Zvi. Parra-Martinez. Julio. Roiban. Radu. Ruf. Michael S.. Shen. Chia-Hsien. Solon. Mikhail P.. Zeng. Mao. 2021-04-26. Scattering Amplitudes and Conservative Binary Dynamics at $(G^4)$. Physical Review Letters. 126. 17. 171601. 10.1103/PhysRevLett.126.171601. 33988437. 2101.07254. 0031-9007. free.
8. 1410.0239. Monteiro. Ricardo. Black holes and the double copy. Journal of High Energy Physics. 2014. 12. O'Connell. Donal. White. Chris D. 2014. 56. 10.1007/JHEP12(2014)056. 2014JHEP...12..056M. 52994864.