Maxitive Donsker-Varadhan Formulation for Possibilistic Variational Inference
Jasraj Singh, Shelvia Wongso, Jeremie Houssineau, Badr-Eddine Chérief-Abdellatif
TL;DR
This paper extends variational inference to the realm of possibility theory by deriving a maxitive Donsker–Varadhan analogue, enabling principled inference under epistemic uncertainty. It introduces a maxitive posterior $g^{\star}_{\text{max}}$ and a pair of consistency bounds (CBOs) that parallel ELBO/VI bounds in probability theory, along with a unifying framework for exponential-family possibilistic VI. The work shows how conjugate priors and exponential-family forms translate into the possibilistic setting, yielding tractable updates and gradient-based optimisation rules. Overall, the approach provides a robust, non-additive alternative to probabilistic VI with practical gradient-based methods for exponential-family models.
Abstract
Variational inference (VI) is a cornerstone of modern Bayesian learning, enabling approximate inference in complex models that would otherwise be intractable. However, its formulation depends on expectations and divergences defined through high-dimensional integrals, often rendering analytical treatment impossible and necessitating heavy reliance on approximate learning and inference techniques. Possibility theory, an imprecise probability framework, allows to directly model epistemic uncertainty instead of leveraging subjective probabilities. While this framework provides robustness and interpretability under sparse or imprecise information, adapting VI to the possibilistic setting requires rethinking core concepts such as entropy and divergence, which presuppose additivity. In this work, we develop a principled formulation of possibilistic variational inference and apply it to a special class of exponential-family functions, highlighting parallels with their probabilistic counterparts and revealing the distinctive mathematical structures of possibility theory.
