Instantons confined by monopole strings

It is known that monopoles can be confined by vortex strings in d = 3 + 1 while vortices can be confined by domain lines in d = 2 + 1. Here, as a higher dimensional generalization of these, we show that Yang-Mills instantons can be confined by monopole strings in d = 4 + 1. We achieve this by putting the system into the Higgs phase in which the configuration can be constructed inside a non-Abelian vortex sheet. DOI: 10.1103/PhysRevD.87.066008