## Is the light too light?(English)Zbl 1205.83019

Summary: The gravitational interaction of light is analyzed considering its dual characteristic nature, i.e. as an (electromagnetic) wave or as a particle (photon). Considered as an electromagnetic wave, the light can be source of gravitational waves belonging to the larger class of exact solutions of Einstein field equations which are invariant for a non-Abelian two-dimensional Lie algebra of Killing fields. It is shown that in the would be quantum theory of gravity they correspond to spin$$-1$$ massless particles.

### MSC:

 83C05 Einstein’s equations (general structure, canonical formalism, Cauchy problems) 83C35 Gravitational waves 83C22 Einstein-Maxwell equations 83C45 Quantization of the gravitational field 83C15 Exact solutions to problems in general relativity and gravitational theory