compact simple gauge group mass gap Streater & Wightman (1964) Osterwalder & Schrader (1973) Osterwalder & Schrader (1975) group
Prove that for any compact simple gauge group G, a non-trivial quantum Yang–Mills theory exists on 





R


4




{\displaystyle \mathbb {R} ^{4}}

 and has a mass gap Δ > 0. Existence includes establishing axiomatic properties at least as strong as those cited in Streater & Wightman (1964), Osterwalder & Schrader (1973) and Osterwalder & Schrader (1975).
