Machine Learning, Clustering, Gaussian Mixture Model.
likelihood of the y given θ has a lower bound as outlined in Eq 5. Moreover, the second term of Equation 5 is essentially the KL divergence between q(z)and p(z|y, θ), and it is always non-negative. Therefore, the lower bound can be reduced to just the first term, which we denote as F(q(z), θ). You