Chandrasekhar's white dwarf equation

Summary

Chandrasekhar's white dwarf equation is the ordinary differential equation for a star held up by the pressure of a cold, degenerate electron gas. It allows the electrons to move at relativistic speeds. It replaces the power law of a polytrope by the exact pressure of such a gas. In the low-density limit it becomes the Lane–Emden equation of index $3/2$, and in the high-density limit the one of index $3$. Its solutions give the relation between mass and radius of white dwarfs and the Chandrasekhar limit.