Hi everyone--I'm curious why terms in the Lagrangian with mass dimension greater than four are "nonrenormalizable."(adsbygoogle = window.adsbygoogle || []).push({});

I understand that the action must be dimensionless, hence the Lagrangian [density] has mass dimension 4. However, in effective field theories, we can end up with terms of dimension > 4, hence the coupling must have negative dimension. What's so bad about this?

(I guess somehow the renormalization group flow for such coupling constants diverges a mass scale given by the coupling?)

Thanks,

Flip

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# Why are dimension > 4 operators non-renormalizable?

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