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"To pursue a PhD in theoretical high-energy physics, one needs to be half retarded and half advanced -- half-advanced for wanting to capture the excitement of the past, and half retarded for seeing a future in it." ;-)


Jun
28
comment Doubts with basic renormalization
Try one of the more recent books (there's been a surge of QFT textbooks in the last few years) -- one of them might have a more modern viewpoint. Alternatively, here are some of the EFT reviews; pick one you like: inspirehep.net/search?ln=en&p=65027a%3AI-c-11
Jun
28
revised Doubts with basic renormalization
added 579 characters in body
Jun
28
comment Doubts with basic renormalization
It's just something I came up with to phrase my understanding, once things finally clicked. I also love it, because it allows me to capture the sentiment :-)
Jun
26
comment What happens to theoretical physics if a photon has non-zero mass?
The photon can acquire an effective mass due to a few different mechanisms, which respectively cause the following effects: 1. en.wikipedia.org/wiki/Meissner_effect 2. en.wikipedia.org/wiki/Debye_length
Jun
25
comment Doubts with basic renormalization
Just out of curiosity: Which QFT texts are you talking about?
Jun
25
answered Doubts with basic renormalization
Jun
25
comment Ice bath is always 3C, why?
+1! I think this is very important to bear in mind because we seem to be in a rush to prefer "digital" devices which have an apparent precision to many decimal points, but the accuracy could be quite bad, like you point out. I have seen many (school/college) students fall for this precision fetish.
Jun
12
awarded  Yearling
May
21
comment What is meant by the phrase “this operator does not renormalize this other operator”, and how can understand it using diagrammatic arguments?
BTW, this recent paper might be of interest: arxiv.org/abs/1505.01844
May
16
comment Can bosons have anti-particles?
Taylor's point seems to be centered on the following idea "Bosons operate under different laws and can be created singly. This is a crucial distinction and is in nature of being either matter particles or force carriers." (which I simply don't understand)
May
16
comment Can bosons have anti-particles?
By definition charge conjugation $C$ is that operator which swaps particles and anti-particles. And I have to agree with @innisfree.
May
16
comment Can bosons have anti-particles?
Would you call the Higgs (doublet; not just the radial mode) an elementary scalar that is electrically carged?
May
15
awarded  Nice Answer
Mar
11
comment Why are $SU(N)$ gauge theories easier to handle for $N\rightarrow \infty$?
It's an expansion parameter, like any other. In the large-N limit, many diagrams become sub-dominant. So it's enough to deal with a dominant diagrams, which are easier to deal with.
Mar
11
revised Why are $SU(N)$ gauge theories easier to handle for $N\rightarrow \infty$?
"Simple" in the context of a lie group means something very specific -- and SU(N) is not "simple" in that sense.
Mar
3
revised What does it mean to have a degenerate $S$-matrix?
deleted 156 characters in body
Mar
3
answered What does it mean to have a degenerate $S$-matrix?
Mar
3
comment Notion of distance in a Conformal Field Theory
To add to my comment above, if distances really did not matter, then you are wrecking serious havoc with the notion of locality/causality! (You most definitely don't do that in a conformal quantum field theory)
Mar
1
comment Notion of distance in a Conformal Field Theory
"In a conformal field theory, due to the scale invariance only angles - and not distances - matter." That's not quite true! All that scale invariance guarantees you is that things transform nicely as you zoom in and zoom out. You don't see something weird happening as you zoom past a special scale. So one can pick a scale unit for calculation, and then ensure that all physical answers are non-dimensionalized by the same unit, so that they respect scale invariance.
Feb
27
awarded  Autobiographer