Past exam of the mathematics course of the University of Cambridge 2023 iii Paper 307 2 ii Solution 2026-09-28
For and distinct masses, any nonzero charged field can occur only at one . At such a point, D-flatness gives , whereas F-flatness gives ; together they force both fields to vanish. Thus only the Coulomb branch remains,of complex dimension one. The points are special because the corresponding charged multiplets become massless there.
Past exam of the mathematics course of the University of Cambridge 2023 iii Paper 307 2 iii Solution 2026-09-28
When every and vanishes, the Coulomb branch again has and arbitrary . A Higgs branch also occurs at : it is the zero-level quotient ofby U(1), and has complex dimension for . The two branches meet at the origin. For , the F- and D-flat equations force both charged fields to vanish, so the Higgs branch collapses to that intersection point.