I'm learning QFT from Srednicki's book. He introduces dimensional analysis in section 12. Coupling constant needs to be dimensionless in order to avoid a number of problems. So phi-cubed theory needs 6 space time dimensions to make sense, but isn't phi-4th-powered theory just right for our 4 space time dimensions? Why to use phi-cubed theory?(adsbygoogle = window.adsbygoogle || []).push({});

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# Dimensional analysis and coupling constant

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