1204.6709 (S. I. Kruglov)

Modified gravity: $F(R)=R\exp(αR)$    [PDF]

S. I. Kruglov

A novel modified theory of gravity with the function $F(R) = R\exp(\alpha R)$ instead of Ricci scalar $R$ in the Einstein$-$Hilbert action is suggested and analyzed. The action is converted into Einstein$-$Hilbert action at small value of the parameter $\alpha$. From local tests we obtain a bound on the parameter $\alpha\leq 10^{-6}$ cm$^2$. The Jordan and Einstein frames are considered and the potential of the scalar field in Einstein's frame is found. The static solutions of the model are obtained corresponding to the Schwarzschild$-$de Sitter space. We show that the de Sitter space is unstable but a solution with zero curvature is stable. It was demonstrated that the model passes the matter stability test.

View original: http://arxiv.org/abs/1204.6709