# Pair Production via Black Hole

I think this should be a straight forward question. Is it possible for a photon to pass near a black hole and be turned into a matter and anti-matter pair according to current theory?

Edit: From the comments I understand the above is thought to be possible, but extremely rare/unlikely. I didn't realize that the black hole may need to be charged though. Is it a requirement that the black hole be charged?

• If the black hole were big enough, then its radius of curvature near the event horizon is sufficiently small to only provide weak corrections to the predictions of quantum field theory. In such cases, I presume this possible. Note however, that even in flat space-time the process you mention is not kinematically allowed, so all you can do is to produce a virtual pair which must then immediately (with some probability) annihilate back into a photon. Apr 25, 2016 at 4:17
• @Prahar Thanks, I am trying to understand but I find your comment enigmatic. If a virtual pair is thus created would it be the case that at least one of the two also must then immediately (with some probability) get sucked into the black hole? Apr 25, 2016 at 4:39
• You can't say "must" and then say "with some probability". Yes, there does exist a probability of one of the two pairs enters the black hole and the other escapes. This, in fact, leads to Hawking radiation. Apr 25, 2016 at 4:43
• @Prahar Maybe I have misunderstood something. When you write "one of the two pairs", are you referring to 2*2=4 total particles? Apr 25, 2016 at 5:10
• What has the "black hole" to do with this? Pair production happens whenever there's a photon with enough energy and some charged object it can interact with to give the "excess" momentum to that ordinarily forbids pair production from a free photon. Apr 25, 2016 at 10:50