π€ AI Summary
This work proposes a novel flow-based framework for representation learning, designed to efficiently extract sufficient information from data and rigorously test conditional independence. The key innovation lies in the introduction of the βzero-flow criterion,β which leverages the property that the adjusted flow velocity vanishes at time t = 0.5 to construct a computable loss function that obviates the need for sampling or simulation. This enables amortized learning of Markov blankets and self-supervised representation extraction. By extending flow models beyond generative modeling into the domain of representation learning, the method demonstrates strong empirical performance in both conditional independence testing and latent representation learning, as validated on synthetic and real-world datasets.
π Abstract
Flow-based methods have achieved significant success in various generative modeling tasks, capturing nuanced details within complex data distributions. However, few existing works have exploited this unique capability to resolve fine-grained structural details beyond generation tasks. This paper presents a flow-inspired framework for representation learning. First, we demonstrate that a rectified flow trained using independent coupling is zero everywhere at $t=0.5$ if and only if the source and target distributions are identical. We term this property the \emph{zero-flow criterion}. Second, we show that this criterion can certify conditional independence, thereby extracting \emph{sufficient information} from the data. Third, we translate this criterion into a tractable, simulation-free loss function that enables learning amortized Markov blankets in graphical models and latent representations in self-supervised learning tasks. Experiments on both simulated and real-world datasets demonstrate the effectiveness of our approach. The code reproducing our experiments can be found at: https://github.com/probabilityFLOW/zfe.