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Quantum field theory and the renormalization group

  1. Feb 16, 2012 #1
    The following statements are from the paper with the above title, recommended in another
    thread, are from here:

    http://fds.oup.com/www.oup.co.uk/pdf/0-19-922719-5.pdf [Broken]

    An interpretion of these statements would be appreciated:

    [first paragraph, page 3] What is 'conservation of the number of particles'?? Am I supposed to expect that outcome??

    [second paragraph, page 3]
    What is 'short distance structure'...or the lack thereof?

    3.Following these,still page 3, under the title 'Gauge Symmetries' a discussion ensues regarding non relativistic quantum mechanics but suddenly the final sentence switches to a relativistic interpretation of vector potential. What's happening here? Is the prior discussion
    not relevant??

    and following immediately in "Units of relativistic Quantum theory" we have this statement:

    Is this considered 'relativistic'?? why would they not use
    E2 = [pc]2 + m2c4

    or do you think they are just interested in 'units'??

    4. Has anyone read the whole paper...IS it worthwhile??
    Last edited by a moderator: May 5, 2017
  2. jcsd
  3. Feb 16, 2012 #2


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    I haven't read the whole thing but I've glanced through it. I'd say it's unusually well written, and succeeds in describing some rather advanced topics without delving into too much mathematics.
  4. Feb 16, 2012 #3


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    In non-relativisitic physics, particle number is conserved. In relativistic physics, colliding 2 particles together can create more than 2 particles, because kinetic energy can be changed into matter, so particle number is not conserved.

    Short distance structure means a point particle that cannot be broken into constituent parts. In quantum field theory, this means that the field is a fundamental "thing" (not made of other fields). Locality also refers to the fact that waves of the field must travel at less than the speed of light, so a disturbance at one point in space is local, since it cannot affect a far away region immediately.

    He's just giving a bunch of different examples in physics of "gauge" which just means the same physics is represented by many different mathematical expressions.

    Yes, he was just interested in units.
  5. Feb 18, 2012 #4
    atyy...appreciate you help...thank you.
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