  In principle a minimal extension of the standard model of Particle Physics,
the two Higgs doublet model, can be invoked to explain the scalar field
responsible of dark energy. The two doublets are in general mixed. After
diagonalization, the lightest CP-even Higgs and CP-odd Higgs are jointly taken
to be the dark energy candidate. The dark energy obtained from Higgs fields in
this case is indistinguishable from the cosmological constant.
