# Stress-energy tensor

The stress-energy tensor ${\displaystyle T_{\alpha \beta }}$ encodes both conservation of energy and conservation of momentum via the pointwise conservation law

${\displaystyle \partial ^{\alpha }T_{\alpha \beta }=0.}$

It can be constructed from any geometric (i.e. diffeomorphism-covariant) Lagrangian equation via Noether's theorem.