Physics Stack Exchange is a question and answer site for active researchers, academics and students of physics. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

light has a non-zero energy-stress tensor, so a flux of radiation will slightly affect curvature of spacetime

Question: assume a flux of radiation in the $z$ direction, in flat Minkowski space it will propagate and spread slightly in the $x$ and $y$ directions. But what happens if we take into account self-gravitational effects of light onto itself? will the radiation flux self-gravitate and eventually reconverge?

share|cite|improve this question
Very nice question +1. Do they spread because of quantum loop box diagrams? What about the polarization of the photons? – Diego Mazón Sep 21 '12 at 3:35
There is an answer here: – Jimmy360 May 31 '15 at 22:25

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Browse other questions tagged or ask your own question.