Godel-type universe in f (R, G) gravity

In the current study, we discuss Godel-type universe in f (R, G) gravity. Analysis has been done by considering anisotropic and perfect fluid distributions. Energy conditions for two proposed f (R, G) gravity models have been studied for suitable values of model parameters. Furthermore, Tolman-Oppenheimer-Volkoff equation has been developed with cylindrical coordinates in f (R, G) gravity. The graphical analysis for both these models suggests that Tolman-Oppenheimer-Volkolf equation is obeyed in a specific interval for the radial coordinate r. A polytropic, equation of state has been discussed for two f (R, G) gravity models. By analyzing the energy conditions, it is concluded that Godel-type universe with both f (R, G) gravity models supports the expansion of the universe for certain range of radial coordinates.