\[
\textbf{General Relativity Summary}
\]
\text{Einstein’s general relativity describes gravity as the curvature of spacetime caused by mass and energy.}
\[
R_{\mu\nu} – \frac{1}{2} R\, g_{\mu\nu} + \Lambda g_{\mu\nu} = \frac{8\pi G}{c^4} \, T_{\mu\nu}
\]
\text{where:}
\]
\begin{align*}
R_{\mu\nu} &\text{ is the Ricci curvature tensor} \\
R &\text{ is the Ricci scalar curvature} \\
g_{\mu\nu} &\text{ is the metric tensor describing spacetime geometry} \\
\Lambda &\text{ is the cosmological constant} \\
G &\text{ is the gravitational constant} \\
c &\text{ is the speed of light} \\
T_{\mu\nu} &\text{ is the stress-energy tensor (matter and energy)}
\end{align*}
\[
\text{The presence of mass and energy tells spacetime how to curve, and curved spacetime tells objects how to move.}
\]
