Gravitational interaction of antimatter

Antimatter
A Feynman diagram showing the annihilation of an electron and a positron (antielectron), creating a photon that later decays into an new electron–positron pair.
Antiparticles

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The gravitational interaction of antimatter with matter or antimatter has been observed by physicists.[1] As was the consensus among physicists previously, it was experimentally confirmed that gravity attracts both matter and antimatter at the same rate within experimental error.

Antimatter's rarity and tendency to annihilate when brought into contact with matter makes its study a technically demanding task. Furthermore, gravity is much weaker than the other fundamental forces, for reasons still of interest to physicists, complicating efforts to study gravity in systems small enough to be feasibly created in lab, including antimatter systems. Most methods for the creation of antimatter (specifically antihydrogen) result in particles and atoms of high kinetic energy, which are unsuitable for gravity-related study.[2]

Antimatter is gravitationally attracted to matter. The magnitude of the gravitational force is also the same. This is predicted by theoretical arguments like the gravitational equivalence of energy and matter, and has been experimentally verified for antihydrogen. However the equivalence of the gravitational acceleration of matter to matter vs antimatter to matter has an error margin of about 20% ([1] table 3). Difficulties in creating quantum gravity models have led to the idea that antimatter may react with a slightly different magnitude.[3]

  1. ^ a b Andersson, E. K.; Baker, C. J.; Bertsche, W.; Bhatt, N. M. (September 27, 2023). "Observation of the effect of gravity on the motion of antimatter". Nature. 621 (7980): 716–722. Bibcode:2023Natur.621..716A. doi:10.1038/s41586-023-06527-1. PMC 10533407. PMID 37758891.
  2. ^ Bertsche, W E (6 October 2015). "Physics With Antihydrogen". Journal of Physics B: Atomic, Molecular and Optical Physics. 48 (23). Bibcode:2015JPhB...48w2001B. doi:10.1088/0953-4075/48/23/232001. S2CID 54550833.
  3. ^ Nieto, M. M.; Hughes, R. J.; Goldman, T. (March 1988). "Gravity and Antimatter". Scientific American. Retrieved December 21, 2016.