<math>EI\approx \ln\left(\frac{L^n}{(2\pi e)^{m/2}}\right)+\frac{1}{2}\mathbb{E}_{\mathbf{x}\sim U ([-\frac{L}{2},\frac{L}{2}]^n)}\ln\left|\det\left(\frac{\partial_\mathbf{x} f(\mathbf{x})}{\Sigma^{1/2}}\right)\right|^2, | <math>EI\approx \ln\left(\frac{L^n}{(2\pi e)^{m/2}}\right)+\frac{1}{2}\mathbb{E}_{\mathbf{x}\sim U ([-\frac{L}{2},\frac{L}{2}]^n)}\ln\left|\det\left(\frac{\partial_\mathbf{x} f(\mathbf{x})}{\Sigma^{1/2}}\right)\right|^2, |