\oiintThe \oiint command in LaTeX is used to represent a double integral over a closed surface. It is often used in vector calculus, particularly in the context of Stokes' theorem or Gauss's theorem, where the integration is performed over a closed surface.
Surface integral of a vector field over a closed surface S.
\oiint_S \vec{F} \cdot d\vec{S}Integration of a differential form \omega over the boundary of a volume V.
\oiint_{\partial V} \omegaIntegration of the stress tensor T over a closed surface \Sigma.
\oiint_{\Sigma} T_{ij} n_j \, dS