Photons emit gravitons

Particle physics

The gravitational force between two mass-afflicted particles, which are at a distance \ (r \) from each other, is proportional to the product of the particle masses and inversely proportional to the square of their distance. Thus, the gravitational interaction has an infinite range and, just like the electromagnetic interaction, can be described with the classic field line model.

One could now come up with the idea of ​​describing the gravitational interaction on the level of the elementary particles, analogous to the electromagnetic interaction, also through the exchange of a massless messenger particle, the so-called graviton. The exact elaboration of this description has not yet succeeded, however, because the gravitational interaction is based on a different physical principle than, for example, the electromagnetic interaction:

The electromagnetic interaction is mediated by messenger particles moving in space-time, while with the gravitational interaction the space-time itself moves and bends. The hypothetical graviton is being searched intensively, but it has not yet been discovered.

In addition, there is no known charge associated with the gravitational interaction. The mass cannot be the charge belonging to the gravitational interaction, since it is not a conserved quantity, which is a requirement for a charge in the sense of the Standard Model.

In addition, there are no negative masses, which is why the gravitational interaction, in contrast to the three fundamental interactions of the Standard Model, can only produce attractive and not repulsive forces. Anti-particles therefore have the same positive mass as the associated particles. If the mass were a charge in the sense of the Standard Model, it would have to change its sign between particle and anti-particle.