Cosmological evolution in exponential gravity

Abstract

We explore the cosmological evolution in the exponential gravity $f(R)=R +c_1\n(1-e^{- c_2 R})$ ($c_{1, 2} = \\mathrm{constant}$). We summarize various\nviability conditions and explicitly demonstrate that the late-time cosmic\nacceleration following the matter-dominated stage can be realized. We also\nstudy the equation of state for dark energy and confirm that the crossing of\nthe phantom divide from the phantom phase to the non-phantom (quintessence) one\ncan occur. Furthermore, we illustrate that the cosmological horizon entropy\nglobally increases with time.\n