Submartingale Property of E_0 Under The Polarization Transformations

Mine Alsan, Emre Telatar

We prove that the relation $E_0(\rho ,W^{-})+E_0(\rho ,W^{+})\ge 2E_0(\rho ,W)$ holds for any binary input discrete memoryless channel $W$, and $\rho \ge 0$.