In Grand Unified Theories, these particles are represented as a topological defect in a compact U(1) gauge theory and have a variant named for ‘t Hooft and Polyakov (15[1])which don’t necessitate breaking gauge symmetry. In one formulation two of these particles are connected by a Dirac string, which can act as a solenoid to cause the Aharonov-Bohm effect. The presence of these particles causes a nonzero first term in a certain series expansion on the (*) magnetic field that is typically expressed with spherical harmonics. Dirac showed that these particles lead to the quantization of electric charge. (-5[1])These particles would add a current density term to the 2nd of Maxwell’s equations, whose typical form implies these particles don’t exist. For 10 (10[1])points, name these hypothetical particles that hold magnetic charge. ■END■ (0[1])