I am talking my particualr example. Indeed for any omega I have:
$$N \log(\sigma) + \frac{1}{2\sigma^2} \sum_{i=1}^N (X_i (\omega) - \mu)^2 & = N \log(\sigma') + \frac{1}{2\sigma'^2} \sum_{i=1}^N (Y_i (\omega) - \mu')^2 \\
N \log(\sigma) + \frac{N}{2\sigma^2} \left(\frac{1}{N}\right) \sum_{i=1}^N (X_i (\omega) - \mu)^2 & = N \log(\sigma') + \frac{N}{2\sigma'^2} \left(\frac{1}{N}\right) \sum_{i=1}^N (Y_i (\omega) - \mu')^2$$