  We describe embeddings of $n$-dimensional Lorentzian manifolds, including
Friedmann-Lema\^itre-Robertson-Walker spaces, in $\mathbb{R}^{n+2}$ such that
the metrics of the submanifolds are inherited by a restriction from that of
$\mathbb{R}^{n+2}$, and the action of the linear group SO$(2, n)$ of the
ambient space reduces to conformal transformations on the submanifolds.
