So my trek started out with a desire to derive the Chandrasekhar limit, but I wanted to tackle an astrophysics problem using GR, and a neutron star seemed like the thing to do at the time. Treating the star like a "gas" of neutrons, and calculating the Fermi degeneracy pressure, I would like to compare the Fermi pressure with the gravitational pressure inside the star. I read about the Tolman-Oppenheimer-Volkoff limit (A little), but can't find too much about their derivation of their dP/dr equation. If I treated the neutron star as a schwarzschild solution, how would I go about finding the pressure inside the star due to the gravitational attraction? I thought about running it through Einstein's equation and extracting the pressure terms from the stress-energy-momentum tensor, but remembered it's a vacuum solution, and that wouldn't help me (It's been a while since I used any GR). Any ideas? Areas to explore? I'm not looking for a solution, but some help/advice would be great. Thank you.