The TOV equation, https://en.wikipedia.org/wiki/Tolman%E2%80%93Oppenheimer%E2%80%93Volkoff_equation.
For a real example?
dP(r)/dr=-G/c^2 (((c^2 ?(r))(c^2 M(r)+4?r^3 P(r))))/(r(c^2-2Gm(r)))
dM(r)/dr=4?r^2 ?(r)
3P(r)=?(r)
M(0)=0
P(R)=0
?(0)=?_0
in which?G is Gravitational constant?approximately 6.673×10?11 N·(m/kg)2?and c is Speed of light?approximately 3×10 8 m/s, R&?_0 are two constant which can be self selected. I try to solve this equation through NDSolve function,but do not get the correct M-r revelation.The Output is {}. Please give me some advices, thank you! \(???)/