Four-dimensional N=4 super Yang-Mills theory Created 2026-10-05 Updated 2026-10-06
A four-dimensional supersymmetric gauge theory has one supersymmetric vector multiplet containing a gauge boson, four Weyl spinors, and six real scalar fields in the adjoint group representation. Its massless helicity multiplicities are from helicity to .
Past exam of the mathematics course of the University of Cambridge 2025 iii Paper 307 1 v Solution Created 2026-09-24 Updated 2026-09-25
With canonical normalization, the renormalizable supersymmetric gauge theory hasThe first term is the gauge-covariant Kähler potential and the second is the Supersymmetric Yang-Mills action. A holomorphic superpotential would also be integrated as , but one commuting field in the fundamental representation of admits no nonconstant renormalizable gauge-invariant superpotential: the apparent cubic vanishes.
Seiberg–Witten theory 2026-10-14
In four-dimensional supersymmetric gauge theory, Seiberg–Witten theory determines exact low-energy quantities from the geometry of the vacuum parameter space. For rank one, the central charge in supersymmetry is proportional to , with integral electric and magnetic charges and the dual scalar period. The BPS bound in supersymmetry fixes the mass of a short state by this charge combination. Its vanishing identifies loci where a magnetic monopole or dyon can become massless, even when the original electric description is strongly coupled.
Ten-dimensional super Yang-Mills theory 2026-10-14
Minimal ten-dimensional supersymmetric gauge theory contains a gauge field and an adjoint Majorana-Weyl spinor. They have eight propagating bosonic and eight propagating fermionic states per gauge generator and sixteen real supercharges. A toroidal zero-mode dimensional reduction to four dimensions gives one gauge field, six real adjoint scalar fields, and four adjoint Weyl spinors: a four-dimensional N=4 super Yang-Mills theory. The internal field strength gives the nonnegative scalar potential , where the norm uses a positive invariant inner product on the Lie algebra. Its minima are commuting tuples of adjoint scalar fields.