It seems that in common ways how to produce light (electromagnetic waves, photons) must be involved particles with electric charge: accelerating electrons, spontaneous or stimulated emission, gamma rays from (charged) nuclei. Is it possible to create a photon without electric charge?

Two or three ways came to my mind:

1. anihilation of neutron and anineutron which would produce two photons
2. Hawking radiation of black holes (virtual pair of photons is created in vacuum just above the horizon and one of them is captured by the black hole)
3. rare mode of free neutron decay to proton, electron and electron antineutrino plus gamma ray, but in this case - according to Wikipedia - "gamma ray may be thought of as a sort of "internal bremsstrahlung" that arises as the emitted beta particle interacts with the charge of the proton in an electromagnetic way".

It seems that in common ways how to produce light (electromagnetic waves, photons) must be involved particles with electric charge: accelerating electrons, spontaneous or stimulated emission, gamma rays from (charged) nuclei. Is it possible to create a photon without electric charge?

Two or three ways came to my mind:

1. annihilation of neutron and antineutron which would produce two photons
2. Hawking radiation of black holes (virtual pair of photons is created in vacuum just above the horizon and one of them is captured by the black hole)
3. rare mode of free neutron decay to proton, electron and electron antineutrino plus gamma ray, but in this case - according to Wikipedia - "gamma ray may be thought of as a sort of "internal bremsstrahlung" that arises as the emitted beta particle interacts with the charge of the proton in an electromagnetic way".