Thermodynamics of Apparent Horizon in Brane World Scenarios

Applying the Clausius relation, δQ = TdS, to the apparent horizon of FRW universe in brane world scenarios, we show that an explicit entropy expression associated with the apparent horizon can be obtained. On the apparent horizon, the relation, dE = TdS + WdV, also holds in the brane world scenarios. We show these results in the RSII model, warped DGP model and the more general case with a Gauss-Bonnet term in the bulk and an intrinsic curvature term on the brane.