Formula_5310

\[\Delta f=\nabla_{i} \nabla^{i} f=\operatorname{div}(\operatorname{grad} f)=\frac{1}{\sqrt{|g|}} \frac{\partial}{\partial x^{i}}\left(\sqrt{|g|} g^{i j} \frac{\partial f}{\partial x^{j}}\right),\]