2 problems

Consider a four-dimensional Yang–Mills theory with a simple or semi-simple gauge group spontaneously broken to a subgroup containing at least one $U(1)$ factor, so that the effecti…

Montonen–Olive conjecture. In the simplest version, a sector with label $(m,n)$ should be equivalent, in a suitable sense, to the sector with label $(n,-m)$, with electric and magn…