Statefinder diagnosis for the Palatini f(R) gravity theories

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The Palatini f(R) gravity, is able to probably explain the late time cosmic acceleration without the need for dark energy, is studied. In this paper, we investigate a number of f(R) gravity theories in Palatini formalism by means of statefinder diagnosis. We consider two types of f(R) theories: (i) f(R)=R+αRᵐ-βR⁻ⁿ and (ii) f(R)=R+αln R+β. We find that the evolutionary trajectories in the s-r and q-r planes for various types of the Palatini f(R) theories reveal different evolutionary properties of the universe. Additionally, we use the observational H(z) data to constrain models of f(R) gravity.