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Sep 24, 2018 at 6:01 history tweeted twitter.com/StackPhysics/status/1044104428842872832
Sep 19, 2018 at 4:27 answer added wcc timeline score: 0
Sep 18, 2018 at 16:08 vote accept DanielSank
Sep 18, 2018 at 15:59 history edited DanielSank CC BY-SA 4.0
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Sep 18, 2018 at 11:55 comment added Emilio Pisanty Just for the record, I think the time-ordering issues have been perfectly well handled here, and they do not even need the condition $[V(t),V(t')]=0$ to work. Explicit time-ordering requirements come in if you want to re-express the (infinite) Dyson series as an exponential, but that's not been done here. The requirement that $0\leq t'' \leq t' \leq t$ is plenty obvious in the integration throughout the question.
Sep 18, 2018 at 9:48 history edited Emilio Pisanty CC BY-SA 4.0
Removed ugly space at the top of the post caused by the mathjax-on-its-own-line.
Sep 18, 2018 at 9:48 answer added Emilio Pisanty timeline score: 5
Sep 18, 2018 at 4:52 comment added DanielSank @IamAStudent Perhaps the notation I used isn't clear, but the second integral goes from $0$ to $t'$, so the constrained ordering you have written is there.
Sep 18, 2018 at 4:49 comment added wcc I think we do...In the perturbative expansion, the integration limit tells us that $0 \leq t' \leq t$ and $0 \leq t'' \leq t'$ so $0 \leq t'' \leq t' \leq t $ but this is not apparent in the final expression. Regarding the book, If you can't find it I will give a try tomorrow at working out what I mentioned (or least provide the expressions from the book to work on)
Sep 18, 2018 at 4:39 comment added DanielSank @IamAStudent thanks for the comments. I don't think we need time ordering here because $[V(t), V(t')]=0$ for all $t$ and $t'$. I appreciate the reference. Will see if a coworker has the book.
Sep 18, 2018 at 4:33 comment added wcc I think the Dyson series integral should have time ordering. Also, Cohen-Tannoudji works out the transition amplitude for second order transition in pg 28-30 of "Atom-Photon Interaction" for time-independent $\hat{V}$, and I feel the generalization to time-dependent case should be straightforward. The drive frequency should appear in the $\delta^{(T)}(E-E_{f,i})$ that he talks about, and the right choice of drive frequency should maximize the value of the product of two $\delta^{(T)}$.
Sep 18, 2018 at 3:50 history asked DanielSank CC BY-SA 4.0