Besides the Wu-Yang and t'Hooft-Polyakov varieties, a dyon with no electrical charge is one of them.
In Grand Unified models, these particles catalyze proton decay in the Callan-Rubakov effect. One variety of them emerges and disappears in a tunneling event between two Gribov vacua, and in a 3-dimensional gauge theory with a Higgs field, one variety of them takes the role of an instanton. Besides the Wu-Yang and t'Hooft-Polyakov varieties, a dyon with no electrical charge is one of them. A curve from one of these to infinity is known as the Dirac string, while the Dirac one is a topological defect in compact U(1) gauge theories. Their existence would change the right hand side of Gauss's law and explain the quantization of electric charge. For 10 points, name these hypothetical particles which would be units of magnetic charge.
In Grand Unified models, these particles catalyze proton decay in the Callan-Rubakov effect.
Magnetic monopoles