Journal of the Korean Physical Society vol. 45, no. SUPPL., pp. S95 - S98
SCI; SCIE; SCOPUS; KCI
We study the Friedmann-Robertson-Walker cosmological model to investigate non-smooth curvatures associated with multiple discontinuities involved in the evolution of the universe, by exploiting a Lorentzian warped product scheme. Introducing double discontinuities occurring at the radiation-matter and matter-lambda phase transitions, we also discuss non-smooth features of the spatially flat Friedmann-Robertson-Walker universe.