Buchdahl, by imposing a few physical assumptions on the matter, i.e., its density is a nonincreasing function of the radius and the fluid is a perfect fluid, and on the configuration, such as the exterior is the Schwarzschild solution, found that the radius $r_0$ to mass $m$ ratio of a star would obey the Buchdahl bound $r_0/m\geq9/4$. He noted that the bound was saturated by the Schwarzschild interior solution, the solution with $\rho_{\rm m}(r)= {\rm constant}$, where $\rho_{\rm m}(r)$ is the energy density of the matter at $r$, when the central central pressure blows to infinity... (read more)

PDF Abstract- GENERAL RELATIVITY AND QUANTUM COSMOLOGY

- SOLAR AND STELLAR ASTROPHYSICS

- HIGH ENERGY PHYSICS - THEORY

- MATHEMATICAL PHYSICS

- MATHEMATICAL PHYSICS