Posterior Collapse
Posterior collapse, a phenomenon where the learned latent representations in variational autoencoders (VAEs) and related generative models become independent of the input data, is a significant challenge hindering effective representation learning. Current research focuses on understanding the causes of posterior collapse in various architectures, including VAEs, conditional VAEs, hierarchical VAEs, and latent diffusion models, and developing methods to mitigate it, such as contrastive regularization, KL annealing, and inverse Lipschitz constraints on decoder networks. Addressing posterior collapse is crucial for improving the performance and reliability of generative models and representation learning techniques across diverse applications, from image generation and time-series analysis to multi-agent interaction modeling.