I wouldn't say I'm looking for anything.
I was thinking that some of the more complex feynman diagrams were essentially computationally intractable due to their combinatoric complexity. Thus as skeptical as I am of these claims, can we necessarily exclude low energy photon-photon interaction?
Or is it correct to say that if we've worked out all the interactions with a small number of particles we can exclude these sorts of interactions with larger numbers of particles?
Is it something like interactions involving large numbers of particles become vanishingly improbable?
I'm not looking to attract any flame here, I'm just interested in understanding this a little better.