Accelerated expansion of the Universe in Gauss-Bonnet gravity

We show that in Gauss-Bonnet gravity with negative Gauss-Bonnet coefficient and without a cosmological constant, one can explain the acceleration of the expanding Universe. We first introduce a solution of the Gauss-Bonnet gravity with negative Gauss-Bonnet coefficient and no cosmological constant term in an empty (n+1)-dimensional bulk. This solution can generate a de Sitter spacetime with curvature n(n+1)/{(n-2)(n-3)|α|}. We show that an (n-1)-dimensional brane embedded in this bulk can have an expanding feature with acceleration. We also considered a four-dimensional brane world in a five-dimensional empty space with zero cosmological constant and obtain the modified Friedmann equations. The solution of these modified equations in matter-dominated era presents an expanding Universe with negative deceleration and positive jerk which is consistent with the recent cosmological data. We also find that for this solution, the “n” th derivative of the scale factor with respect to time can be expressed only in terms of Hubble and deceleration parameters.