Gravitons are hypothetical particles that are postulated in the framework of quantum field theory to mediate the force of gravity. According to this theory, all forces in nature are transmitted through the exchange of fundamental particles called gauge bosons.
In the case of electromagnetism, the force between electrically charged particles is mediated by photons. Similarly, the strong nuclear force is mediated by gluons, and the weak nuclear force is mediated by W and Z bosons. In the context of gravity, the graviton is the hypothetical particle that is thought to mediate the gravitational force.
Quantum field theory describes particles and their interactions in terms of fields. In this framework, the gravitational field is quantized, and the corresponding quanta of this field are gravitons. Gravitons are considered to be spin-2 particles, which means they have two units of intrinsic angular momentum, or spin.
The interaction between particles through the exchange of gravitons is responsible for the gravitational force. Just as photons mediate the electromagnetic force by interacting with charged particles, gravitons mediate the gravitational force by interacting with particles that possess mass or energy. However, it's important to note that the quantum theory of gravity, including the graviton, is still a topic of ongoing research and has not been fully developed or experimentally confirmed.
It is worth mentioning that the nature of gravitons and the complete understanding of quantum gravity is an active area of theoretical physics and remains an open question. The current formulation of gravitons and their role in mediating gravity is based on theoretical frameworks like perturbative quantum gravity and string theory, but a complete and experimentally validated theory of quantum gravity is yet to be established.