Number of distinct diagrams.

  1. I was just trying to think of a simple relation to find the number of distinct diagrams to a given order within a theory (specifically I am thinking of a [tex]\phi^{4}[/tex] scalar theory). I am reading Tony Zee's book and am working through his "baby problem" where he expands the integral:

    [tex]\int_{-\inf}^{\inf} dq e^{-\frac{1}{2}m^{2}q^{2}+Jq-\frac{\lambda}{4!}q^{4}[/tex]

    in both in powers of [tex]\lambda[/tex] and J so that we can pick out diagrams to a specific order in both.

    So is there a way to find the total number of distinct diagrams to order [tex](\lambda^{n},J^{m})[/tex]?

    Thanks in Advanced :smile:
  2. jcsd
  3. to be honest, i have no idea.
  4. K^2

    K^2 2,470
    Science Advisor

    From personal experience, you just keep working these out by hand until you see a pattern. Or you get to a point where you give up. If there is a better way, I have not found it.
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