# The cosmic equation of state

@article{Melia2014TheCE,
title={The cosmic equation of state},
author={Fulvio Melia},
journal={Astrophysics and Space Science},
year={2014},
volume={356},
pages={393-398}
}
• F. Melia
• Published 21 November 2014
• Physics
• Astrophysics and Space Science
The cosmic spacetime is often described in terms of the Friedmann-Robertson-Walker (FRW) metric, though the adoption of this elegant and convenient solution to Einstein’s equations does not tell us much about the equation of state, p=wρ, in terms of the total energy density ρ and pressure p of the cosmic fluid. ΛCDM and the Rh=ct Universe are both FRW cosmologies that partition ρ into (at least) three components, matter ρm, radiation ρr, and a poorly understood dark energy ρde, though the…
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