Answer:
Black hole is described by singularity of Schwarzchild's equation.
[tex]R_{Sch}=\frac{2GM}{c^2}[/tex]
Explanation:
Einstein's field equations consists of 10 sets of equations describing general relativity: Space time curves in presence of mass and energy.
[tex]R_{\mu\nu}-\frac{1}{2}Rg_{\mu\nu}+ \Lambda g_{\mu\nu}=\frac{8\pi G}{c^4}T_{\mu\nu}[/tex]
Condition of black-hole came from Schwarzchild's solution to Einstein's field equation:
[tex]ds^2=(1-\frac{2GM}{c^2r})c^2dt^2-(\frac{1}{1-\frac{2GM}{c^2r}})dr^2-r^2(d\theta^2+sin^2\theta d\phi^2)[/tex]
Black hole is described by singularity of Schwarzchild's equation.
[tex](1-\frac{2GM}{c^2r})=0[/tex]
[tex]R_{Sch}=\frac{2GM}{c^2}[/tex]
It defines the event horizon of the Schwarzchild's black-hole.
