  Scattering amplitudes in Yang-Mills-Einstein theories have been investigated
mostly for compact gauge groups. While non-compact gauge groups are not
physically viable in Yang-Mills theory, non-compact gaugings feature
prominently in the supergravity literature, where any choice of perturbative
vacuum spontaneously breaks the gauge group to a compact subgroup. In this
paper, we formulate double-copy constructions for several five-dimensional N=2
supergravities with non-compact gauge groups. On one side of the double copy,
we employ amplitudes from a super-Yang-Mills theory with a massive
hypermultiplet. On the other, we use amplitudes from particular
non-supersymmetric Yang-Mills-scalar theories with massive fermions, chosen to
obey constraints coming from color/kinematics duality. Supergravities with
massive self-dual tensors in five dimensions are also considered, showing that
tensors are straightforwardly realized as double copies of gauge-theory
fermions with suitable choices of signs in the corresponding solutions of the
Dirac equation. We present several examples of these constructions, noting in
particular the appearance of Heisenberg groups in the supergravity gauge
symmetry and, in some cases, the possibility of exotic tensor-vector matter
couplings.
