Hydrostatic equilibrium and stellar structure in f(R)-gravity
by
Salvatore Capozziello(NA)
→
Europe/Rome
Description
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.
