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I am confused about what gravitons exactly are.

On the one hand it is said that gravitons are presumed to represent gravity (see Wikipedia "Graviton" : "In theories of quantum gravity, the graviton is the hypothetical quantum of gravity, an elementary particle that mediates the force of gravitational interaction.")

On the other hand, gravitons are compared to photons which are representing electromagnetic radiation (see Wikipedia "Electromagnetic radiation" : "In quantum mechanics, an alternate way of viewing EMR is that it consists of photons".)

The point is that electromagnetic waves are generated by accelerating charges and gravitational waves are supposed to be generated by accelerating masses, and as far as I know, gravitational waves are not a direct effect of gravity but an effect of accelerating masses.

So, if gravitational waves are not a direct effect of gravity itself, are gravitons an "alternate way of viewing" gravitational waves or are they a direct effect of gravity?

Qmechanic
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Moonraker
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1 Answers1

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Photons with zero rest mass, travelling at the speed of light, can be used to represent electromagnetic waves caused by accelerating charged particles. Virtual photons are also used to mediate the electromagnetic forces between charged particles.

In analogy, gravitons with zero rest mass, travelling at the speed of light, might be used to represent gravitational waves (produced by certain types of accelerating mass) and virtual gravitons would mediate gravitational forces between masses in a quantum theory of gravity.

See also Are GWs made of gravitons (are gravitons the quanta of GWs) or not?

ProfRob
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