Hey, I'm trying to understand the Elitzur-Vaidman bomb tester since it is an essentially quantum mechanic effect, but I haven't been able to find a technical quantum mechanical treatment of the subject though I've found plenty of non-technical treatments and a few pseudo-classical treatments. The way I understand the setup is that we start with a photon prepared in an entangled state between going on the top and bottom arms of the bomb tester. (Let's call this state |T> + |B>) The bottom photon then encounters a bomb that is live or dead. I suppose I could treat this bomb as an operator, either being a projection operator (live bomb, projects onto |T>) or identity operator (dead bomb), but this would operate on the entire state at once, and that doesn't seem quite right. Then I really don't understand what's going on with the half-silvered mirror at the end. It seems to make the top and bottom arms of the bomb tester recombine and interfere, but I can't figure out what that means in terms of operators. Can someone help me out?