# Equipartition of energy and the first law of thermodynamics at the apparent horizon

We apply the holographic principle and the equipartition law of energy to the apparent horizon of a Friedmann-Robertson-Walker universe and derive the Friedmann equation describing the dynamics of the universe. We also show that the equipartition law of energy can be interpreted as the first law of thermodynamics at the apparent horizon.

**Comments:**v2: 7 pages, 1 figure, add discussion on consistency check, Int. J. Mod. Phys. D in press

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