factual

Coupling gravity bounds gauge group size

Maximally supersymmetric (N=4) gauge theories are finite for any gauge group of any size without gravity, but when you couple them to four-dimensional gravity you can never obtain groups larger than around SU(23); the allowed set is finite while the naive set is infinite, so the consistent-with-gravity theories are a measure-zero subset.

factualpending

Speaker

Cumrun Vafa

Evidence Quote

even though you could have had any end naively from one to infinity consistent with SG one SG two SG3 et cetera up to SG infinity all of them are finite. When you could gravity you have a finite allowed set. So the set of possibilities compared to the totality allowed one is measure zero.

Source

277 | Cumrun Vafa on the Universe According to String TheorySean Carroll's Mindscape
Created: 6/13/2026, 12:07:45 AM

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