6 negative pressure (tension). In this case the tension does not arrive from the negative pressure of dark energy but from the entropic tension due to the entropy content of the horizon surface. This is equivalent to the outward acceleration a$_{H}$ = cH of Eq. (7). If we chose to put the information screens at smaller radii, then, associating entropy with information,we would have found a proportionally smaller pressure, and an acceleration that decreases linearly with the radius in accordance with our expected Hubble law. Thus, the acceleration of the universe simply arises as a natural consequence of the entropy on the horizon of the universe. In this section, we present a specific phenomenological model inspired by surface terms usu- ally ignored in general relativity and show that this also leads to an accelerating universe. While the surface terms source our motivation, the model is best viewed as a phenomeno- logical model which we introduce here without rigorous derivation. We consider the least additional assumption is that general relativity is correct, and that it can be easily under- stood and derived from a variational principle using the action. We show that, under reasonable assumptions, the new terms lead to an acceleration term in the Friedmann-Lemaˆıtre equations. There is a solution to the acceleration equation that evolves from a decelerating to an accelerating phase. Our discussion of surface terms presents a specific class of models that give rise to cosmological acceleration; however, we note that our main result, the derivation of cosmological acceleration as an entropic force presented in the previous section, is model independent. The Einstein-Hilbert action including the surface term and a matter action is (schematically) where R is the scalar curvature, L$_{m}$ is the matter and field Lagrangian, and K is the trace of the extrinsic curvature of the boundary [8]. The application of variational procedures then IV. ACCELERATION FROM THE ENTROPY AND SURFACE TERMS I = ∫ M ( R + L$_{m}$ ) + 1 8 π ∮ ∂M K (12)