# Cardassian expansion: dark energy density from modified Friedmann equations

@article{Freese2005CardassianED,
title={Cardassian expansion: dark energy density from modified Friedmann equations},
author={Katherine Freese},
journal={New Astronomy Reviews},
year={2005},
volume={49},
pages={103-109}
}
• K. Freese
• Published 31 January 2005
• Physics
• New Astronomy Reviews
Abstract The Cardassian universe is a proposed modification to the Friedmann equation in which the universe is flat, matter dominated, and accelerating. In the ordinary Friedmann equation, the right hand side is a linear function of the energy density, H 2  ∼  ρ . Here, instead, the right hand side of the Friedmann equation is a different function of the energy density, H 2  ∼  g ( ρ ). This function returns to ordinary Friedmann at early times, but drives acceleration of the universe at the… Expand
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