− | Eff_F-Eff_f=\frac{EI}{N}-\frac{EI}{n}\approx \frac{N}{n}\int_{-\frac{L}{2}}^{\frac{L}{2}}\ln\frac{\left|\det\left(\frac{\partial_\mathbf{x} f(\mathbf{x})}{\Sigma^{1/2}}\right)\right|^2}{\left|\det\left(\frac{\partial_\mathbf{X} F(\mathbf{X})}{\Sigma_N^{1/2}}\right)\right|^2} d\mathbf{x}
| + | \Delta \mathcal{J}\equiv \frac{\mathcal{J_F}}{N}-\frac{\mathcal{J_f}}{n}\approx \frac{N}{n}\int_{-\frac{L}{2}}^{\frac{L}{2}}\ln\frac{\left|\det\left(\frac{\partial_\mathbf{x} f(\mathbf{x})}{\Sigma^{1/2}}\right)\right|^2}{\left|\det\left(\frac{\partial_\mathbf{X} F(\mathbf{X})}{\Sigma_N^{1/2}}\right)\right|^2} d\mathbf{x} |