Shape operator
= Shape operator
{title2=$S_p$}
= Weingarten map
{c}
{synonym}
The shape operator is an extrinsic-curvature construction in the <differential geometry of surfaces>.
For an <orientation of a surface>[oriented surface] with <Gauss map> $N$, the shape operator at $p$ is the self-adjoint linear map
$$
S_p=-dN_p:T_pS\to T_pS.
$$