# Gravity of Light [duplicate]

I'm reading Quantum field theory in a Nutshell and I find a very interesting calculation that leads to the gravitational interaction between 2 light beam.

Is this kind of interaction permitted in general relativity? (not necessarily a quantum gravity theory or the like) Is there a energy tensor $T_{\mu\nu}$ asscociated with a photon so that it creates $R_{\mu\nu}\ne 0$? It's awesome if someone can give a simple derivation in the framework of general relativity.

• Your photon is a disturbance in an EM field, which $T_{\mu\nu}$ corresponds to, so yes, you should get a non-zero energy-momentum tensor corresponding to the photon. – PPR Aug 16 '14 at 17:15
• Can you explicitly deriving $T_\mu\nu$? Thanks! – Learning Aug 17 '14 at 0:52
• possible duplicate of Do two beams of light attract each other in general theory of relativity? – John Rennie Aug 17 '14 at 10:43