$R_h=ct$ and the eternal coasting cosmological model

Understand

We point out that the nonempty $R_h=ct$ cosmological model has some known antecedents in the literature.

• Some of those eternal coasting models are published even before the discovery of the accelerated expansion of the universe and were shown to have none of the commonly discussed cosmological problems and also that $H_0t_0=1$.
• The $R_h=ct$ model is only the special (flat) case of the eternal coasting model.
• An additional feature in the coasting model is that $\Omega_m/\Omega_{dark \; energy}$ = some constant of the order of unity, so that also the cosmic coincidence problem is avoided.