Abstract: We investigate the hydrostatic equilibrium of stellar structure by taking into account the modified Lane'-Emden equation coming out from f(R)-gravity. Such an equation is obtained in metric approach by considering the Newtonian limit of f(R)-gravity, which gives rise to a modified Poisson equation, and then introducing a relation between pressure and density with polytropic index n. The modified equation results an integro-differential equation, which, in the limit of General Relativity becomes the standard Lane'-Emden equation. We find the radial profiles of gravitational potential by solving for some values of n. The comparison of solutions with those coming from General Relativity shows that they are compatible and physically relevant. This analysis gives rise to unstable modes not present in the standard Jeans analysis (derived assuming Newtonian gravity as weak filed limit of f(R)=R). In this perspective, we discuss several self-gravitating astrophysical systems whose dynamics could be fully addressed in the framework of f(R)-gravity.

Place: Physics Dept. Meeting Room, 2th floor, IST