  A cosmological extension of the Eisenhart-Duval metric is constructed by
incorporating a cosmic scale factor and the energy-momentum tensor into the
scheme. The dynamics of the spacetime is governed the Ermakov-Milne-Pinney
equation. Killing isometries include spatial translations and rotations,
Newton--Hooke boosts and translation in the null direction. Geodesic motion in
Ermakov-Milne-Pinney cosmoi is analyzed. The derivation of the Ermakov-Lewis
invariant, the Friedmann equations and the Dmitriev-Zel'dovich equations within
the Eisenhart--Duval framework is presented.
