  Guided by the analogy with the Rayleigh-Plesset dynamics of multielectron
bubbles in superfluid He-4, we consider the cosmological FLRW evolution
equation with additional cubic and sixth powers of the inverse of the scale
factor of the universe. For the barotropic parameter w=2/3 (coasting universe),
along with zero cosmological constant in the absence of viscous terms, by using
the Sundman time as evolution parameter, we present parametric solutions for
the scale factor of the universe in terms of rational expressions of
Weierstrass elliptic functions and their particular cases thereof. For other
values of the equation of state parameter w, such as w=-1, but also the same
coasting case, we present a more standard discussion in the conformal time
variable using solutions obtained by numerical integration.
