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Sakurai's treatment of Feynman's Path Integral

  1. Oct 19, 2005 #1
    I just finished reading Sakurai's treatment of feynman's path integral, and I'm left feeling really stupid. So the integral gives the propagator, which represents a transition amplitude. I'm left wondering what we use that for. Perhaps I'll understand when I start working some problems, or perhaps after I read the derivation a few more times. But, just to cover my bases, can anybody recommend a different source of the path integral derivation (which, according to sakurai really isn't a derivation)?
  2. jcsd
  3. Oct 19, 2005 #2

    Physics Monkey

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    The propagator is good for a lot of things. It gives you a complete solution to the Schrodinger equation for arbitrary initial conditions so that if [tex] K(x,t;x',t') [/tex] is the propagator then

    [tex] \psi(x,t) = \int dx' \, K(x,t;x',0) \psi(x',0) [/tex]

    and [tex] \psi(x,t) [/tex] satisfies the Schrodinger equation. It can do a lot more too, it encodes all the information about the bound states and their energies.

    Sakurai's treatment is rather terse. A great source for path integrals in general is "Techniques and Applications of Path Integration" by Schulman. A good online source is http://arxiv.org/abs/quant-ph/0004090
  4. Oct 20, 2005 #3
    Go straight to the source, Feynman himself! He is justly well-known for providing good physical pictures behind the math. See the thread "I need some bibliography" for some of his writings ...

  5. Oct 25, 2005 #4
    I recommend the book by Ramond "Quantum field theory, a modern primer"
    Path integral methods is a powerful tool in Quantum field theory,
    particularly in Gauge field theory.
  6. Oct 26, 2005 #5


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    I also like Cohen-Tannoudji's axiomatical treatmeant of path-integrals. In the first volume of his QM book.

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