Superposition of FLRW universes

Heydarzade, Yaghoub
Tekin, Bayram
We show that (1) the Einstein field equations with a perfect fluid source admit a nonlinear superposition of two distinct homogenous Friedman-Lemaitre-Robertson-Walker (FLRW) metrics as a solution, (2) the superposed solution is an inhomogeneous geometry in general, (3) it reduces to a homogeneous one in the two asymptotes which are the early and the late stages of the universe as described by two different FLRW metrics, (4) the solution possesses a scale factor inversion symmetry and (5) the solution implies two kinds of topology changes: one during the time evolution of the superposed universe and the other occurring in the asymptotic region of space.

Citation Formats
M. GÜRSES, Y. Heydarzade, and B. Tekin, “Superposition of FLRW universes,” JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS, no. 6, pp. 0–0, 2020, Accessed: 00, 2020. [Online]. Available: