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    Taking up QFT for the first time

    I'm trying to evade Newton's third law of" ... :biggrin: :bugeye: :!!)
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    Taking up QFT for the first time

    Thanks for the assist :smile: Yes, that was my mistake. Either version j^0=-\imath\left(\pi\phi-\phi^{\dagger}\pi^{\dagger}\right) j^0=-\imath\left(\phi\pi-\pi^{\dagger}\phi^{\dagger}\right) gives the desired result. I also overlooked Greiner's expression eqn. (4.67) giving the charge in...
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    Taking up QFT for the first time

    I'm taking up QFT for the first time. Basic question really. Given the free complex Klein-Gordon field \phi under the global gauge transformation exp(\imath\alpha) where \alpha is some real parameter, the Noether current is given by j^{\mu}=\imath \left( \phi \partial^{\mu} \phi\dagger -...
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    Self-taught Quantum Field Theory

    I'm taking up QFT also. Here's my 2 cents: I find the following books to be useful at my level (introductory) (1) Greiner, Field Quantization: shows you in vivid, explicit detail the requisite calculations. I try to do them first on my own, of course :smile: (2) Ryder, Quantum Field...
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    Why isn't the constant force problem in QM classes?

    See J. J. Sakurai, Modern Quantum Mechanics, revised ed. Problem 24, Chapter 2. :smile:
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    QM mathematics

    Yes, I agree, from a practical point of view real analysis is not needed for calculus, but the suggestion Daniel gave (as I understand it) was to study QM from a axiomatic point of view. I simply recommended doing the "usual" math first... But alas, Art is long and life is short...
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    QM mathematics

    Topology as a mathematical prerequisite for functional analysis, when you start discussing stuff like Lebesque integration, measure theory, L2 spaces, the Riesz-Fischer theorem, generalized functions, etc etc which are required in a rigorous formulation of the math of QM.
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    Starting with QFT

    I'm using Goldstein (2nd ed) to review classical field theory. It seems to work for me. The last chapter discusses the Lagrangian and Hamiltonian formulation of fields, the stress-energy tensor, gives several examples of classical fields (relativistic and non-) and ends with Noether's theorem.
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    QM mathematics

    From someone who knows a little quantum mechanics :wink: here's some advice. For someone just starting out, IMHO starting out with topology to learn the mathematics of QM would probably be... overwhelming. It is certainly possible to approach the subject at different levels of mathematical...
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    QM mathematics

    John Baez has a nice link about "how to learn math and physics". As far as QM is concerned, you will need at least: Calculus Multivariable calculus Linear algebra Ordinary differential equations Partial differential equations Complex analysis
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    Where to start?

    If all you want is a general idea, there are some popular books that discuss QM to some degree like Physics and Philosophy (Heisenberg), The Quark and the Jaguar (Gell-man), Dreams of a Final Theory (Weinberg), A Brief History of Time (Hawking), The Elegant Universe (Greene) etc. There's also...
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    Starting with QFT

    I found this thread very helpful and interesting since I'll be starting on QFT myself in the next few weeks, and I found myself reviewing a lot of stuff. :bugeye: I don't have Zee, so I'll probably be using Schroeder and Peskin (and probably dipping into Bjorken and Drell). I found an eBook on...
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    Delta function & kronecker delta

    Also, both are used to express orthogonality, given a set of vectors, the arguments being the indices of the two vectors in question: the kronecker delta if that set is countable, the delta function if otherwise.
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    What the Bleep Do We Know

    I haven't seen this movie, but "Matter is really more of a thought, or idea, than anything else" seems to mean that the concept of matter is more of an inference rather than something self-evident. I mean, somebody could argue that all we measure really are attributes of matter (color, weight...