Neutrino oscillations in a Robertson-Walker universe with space-time foam

In [J. Alexandre, K. Farakos, N. E. Mavromatos, and P. Pasipoularides, Phys. Rev. D 77, 105001 (2008).] we have studied decoherence models for flavor oscillations in four-dimensional stochastically-fluctuating space times and discussed briefly the sensitivity of current terrestrial and astrophysical neutrino experiments to such models. In this addendum we extend these results to incorporate the effects due to the expansion of the Universe, so that our analysis can be useful in studies of extragalactic high-energy neutrinos, such as those coming from gamma ray bursts at cosmological distances. Unfortunately for some microscopic models of foam, constructed in the string theory framework, we arrive at pessimistic conclusions about the detectability of the decoherence effects via flavor-oscillation measurements.