graviton

American  

[grav-i-ton] / ˈgræv ɪˌtɒn /

noun

Physics.

1. the theoretical quantum of gravitation, usually assumed to be an elementary particle that is its own antiparticle and that has zero rest mass and charge and a spin of two.

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graviton British  

/ ˈɡrævɪˌtɒn /

noun

1. a postulated quantum of gravitational energy, usually considered to be a particle with zero charge and rest mass and a spin of 2 Compare photon

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graviton Scientific  

/ grăv′ĭ-tŏn′ /

1. A hypothetical particle postulated in supergravity theory to be the quantum of gravitational interaction, mediating the gravitational force. Like all force carriers, the graviton is a boson. It is presumed to have an indefinitely long lifetime, zero electric charge, a spin of 2, and zero rest mass (thus travelling at the speed of light). The graviton has never been detected.

2. See also supersymmetry See Table at subatomic particle

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Etymology

Origin of graviton

First recorded in 1940–45; gravit(y) + -on ¹

Example Sentences

A photon, for example, comes from an open string vibrating in its simplest mode, while the graviton is thought to arise from a closed vibrating string.

From Science Daily • May 19, 2026

The team proposed a super-twin for the graviton called the gravitino.

From Nature • Aug. 5, 2019

The main tenet of Superstring theory is that fundamental particles, including the graviton that carries the gravitational force, act like one-dimensional vibrating strings.

From Textbooks • Aug. 12, 2015

“Now we know that gravity is indeed quantized, involving graviton particles,” he added.

From New York Times • Mar. 24, 2014

In the quantum mechanical way of looking at the gravitational field, the force between two matter particles is pictured as being carried by a particle of spin 2 called the graviton.

From "A Brief History of Time: And Other Essays" by Stephen Hawking