Flipped SU(5)
The
Flipped SU(5) model is a
GUT theory which states that the
gauge group is [
SU(5) x
U(1) ]/ and the fermions form three families, each consisting of the
representations , 10
_{1} and 1
_{5}. This includes righthanded neutrinos, which are known to exist because of observed neutrino oscillations. There is also an adjoint
scalar field, a
10_{1} and/or called the Higgs field which acquires a VEV. This results in a
spontaneous symmetry breaking from

to

and also,
 , , , .
Of course, calling the
representations things like and 24
_{0} is purely a physicist's convention, not a mathematician's convention, where representations are either labelled by Young tableaux or Dynkin diagrams with numbers on their vertices, but still, it is standard among GUT theorists.
Since the homotopy group

this model no predicts
monopoles. See HooftPolyakov monopole.
To do:
 This theory was invented by ???.