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Physical interpretation of Feynman path integral

  1. Jun 29, 2004 #1
    What is the physical interpretation of Feynman path integral?
    Thanks :smile:
  2. jcsd
  3. Jun 29, 2004 #2


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    here is one view: it does not have a physical interpretation
    because it is a way of calculating a sometimes very close approximation

    but nature does not know or care how we calculate
    she does something, we dont know exactly how
    and we have this way of calculating that gets the right answer

    it's like virtual particles---maybe they dont exist in nature but they are good to calculate with

    it's like feynmann diagrams: maybe nature doesnt know about them---she doesnt need to because she has her own way of doing things without perturbation series----maybe nothing in nature corresponds to feynmann diagrams---they are useful, tho, for organizing the calculation of a perturbation expansion.

    that is just one viewpoint :smile:
    hopefully someone else will provide a contrasting one

    BTW Feynmann, if you havent already I invite you to have a look in this Quantum Physics forum
    at the electroweak conversation between turin and zephram.
    if zephram answers on this thread it will probably be interesting
    Last edited: Jun 29, 2004
  4. Jun 29, 2004 #3
    But I know that the path integral have a physical interpretation but i don't know
  5. Jun 29, 2004 #4
    hello marcus!
    I'm interested by the subject but I didn't find the post of turin and zephram. Can you give me a link please?
  6. Jun 29, 2004 #5
    Read Feynman and Hibbs' book "Path Integrals." The introduction should satisfy your curiosity.
  7. Jun 29, 2004 #6
    So i don't have the Feynman Hibbs book
    So can u tell me about the physical interpretation of the path integrals :@
  8. Jun 29, 2004 #7
    It relational to the many 'sum-over-history' interpretation also by Feynman.
    For instance:The fundamental question in the path integral (PI) formulation of quantum mechanics is:If the particle is at a position q at time t = 0, what is the probability amplitude that it will be at some other position q0 at a later time t = T?

    This I took from this good paper:http://arxiv.org/PS_cache/quant-ph/pdf/0004/0004090.pdf

    If you read through it, you can form your own viewpoint, interpretation is open to a vast number of probibilities, every path has many (integral-able)(connecting) histories!

    PS the original paper by Feynman was rejected!
  9. Jun 29, 2004 #8
    Dear Olias;
    I see the link. can you tell me how did dirac observed the action plays a central role???
    (also the difference between lagrangian and hamiltonian interpretation)
    Tanks in advanced.
  10. Jun 29, 2004 #9


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  11. Jun 30, 2004 #10
    But I think taht the Feynman path integral is a link between the quantum physics and the quatum field theory, but how????
  12. Jul 1, 2004 #11


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    hi meldi, sorry I didnt respond earlier, I will get a link to that
    electroweak thread in the Quantum Physics forum

    here's the part of my post that I think you are responding to:

    the thread begins here:

    first Duct Taper says something
    then Zephram replies
    then Turin says "I would like to hear a little more..."

    it is really turins perceptive questioning that elicits the good exposition
    that thread is a model of what I wish we had more of
    Last edited: Jul 1, 2004
  13. Jul 1, 2004 #12


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    Yes indeed. I followed that thread and was fascinated by zephram. Thanks zephram.

  14. Jul 3, 2004 #13
    RE: "So i don't have the Feynman Hibbs book "

    Then buy it, or check it out from the library.
  15. Jul 5, 2004 #14
    thank you very much Marcus!
  16. Jul 5, 2004 #15


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    I bought Feynmann Hibbs about ten years ago. I can't really say it helped me understand field theory. The book that really made a breakthrough for me (YMMD) was Hatfield, Quantum Field Theory of Point Particles and Strings. This book is pretty useless as a general reference but it is very intuitive, somewhat in the style of Zefram_C's explanations, but with all the math, too.
  17. Jul 5, 2004 #16


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    Some of Dyson's original papers on the subject are also informative, and quite readable. It explains the link between canonical quantization and the path integral. So if you understand the former things are well off.

    I still love A Zee's book, Quantum field theory in a Nutshell. Its a very quick read, is wonderfully intuitive and quite deep. You pretty much have the path integral thrown at you right from the getgo, and its only a few chapters before its almost fully justified.
  18. Jul 6, 2004 #17
    So gentelmen,
    How we can interprate for exemple the excat solution of Shrodinger equation for harmonic oscilator by Feynmanpath integral?
    which is very complex
  19. Jul 8, 2004 #18
    If i can't buy the book, what i do?
  20. Jul 15, 2004 #19
    what is the probabilisitic point view about path integral?
  21. Jul 26, 2004 #20
    Please what is the probabilisitic point view about path integral?
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