STUDIA MATHEMATICA, cilt.176, sa.1, ss.61-68, 2006 (SCI-Expanded)
Let E be a Riesz space. By defining the spaces L-E(1) and L-E(infinity) of E, we prove that the center Z(L-E(1)) of L-E(1) is L-E(infinity) and show that the injectivity of the Arens homomorphism m: Z(E)" -> Z(E-similar to) is equivalent to the equality L-E(1) = Z(E)'. Finally, we also give some representation of an order continuous Banach lattice E with a weak unit and of the order dual E-similar to of E in L-E(1) which are different from the representations appearing in the literature.