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Latent Dynamics · 2026-10-14

MDN-VJEPA: Multimodal Probabilistic Joint-Embedding World Models

Yongchao Huang

arXiv:2610.13956PDF

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TL;DR

MDN-VJEPA is a multimodal probabilistic world-model based on Joint-Embedding Predictive Architectures (JEPAs). It instantiates the VJEPA latent predictor as a Gaussian-mixture density network (MDN) to represent alternative futures with probabilities and within-mode uncertainty. It adds trajectory-level mode coherence and a distributional multi-horizon path-consistency regularizer for temporal coherence and Chapman–Kolmogorov consistency.

Why it matters

The authors argue that point predictions or unimodal Gaussian predictions can average together valid but distinct futures, producing invalid outcomes in planning. MDN-VJEPA aims to preserve the full multimodal predictive belief (distinct alternatives, their probabilities, and within-mode uncertainty), couple modes coherently across time, and encourage consistency between direct multi-horizon predictions and recursively composed rollouts.

Method

  • Instantiates probabilistic JEPA (VJEPA) with a neural mixture density network: future latent distributions are Gaussian mixtures with component means, covariances, and mixture weights.
  • Enforces trajectory-level mode coherence by selecting a categorical variable once over the prediction horizon so each mixture component parameterizes a whole future trajectory rather than independently per-horizon modes.
  • Adds distributional path-consistency (Chapman–Kolmogorov-motivated) regularization by comparing direct versus recursively composed multi-horizon predictive distributions via a permutation-invariant sample discrepancy.
Abstract (from arXiv)

Joint-Embedding Predictive Architectures (JEPAs) learn world models by predicting future representations rather than reconstructing observations. Variational JEPA (VJEPA) gives this prediction probabilistic semantics and permits flexible conditional predictive families. We propose MDN-VJEPA, a multimodal probabilistic JEPA that instantiates the latent predictor as a mixture density network (MDN), representing future states with a Gaussian mixture whose components encode alternative futures, their probabilities, and within-mode uncertainty. For sequential prediction, we address two additional structural requirements: multi-modal futures should remain temporally coherent across a trajectory, and predictive beliefs should remain consistent when propagated to the same horizon through different temporal path compositions, as motivated by the Chapman--Kolmogorov equation. Together, these considerations define a three-level hierarchy of multimodal prediction, coherent multimodal trajectories, and compositionally consistent multimodal dynamics. Controlled experiments show that MDN-VJEPA closely recovers known branching predictive laws, that retaining the complete multimodal belief rather than its conditional mean can lead to materially different and substantially better planning decisions under branching futures, and that trajectory-level coupling and distributional consistency improve temporal coherence and multi-horizon agreement. These results support a simple principle: a probabilistic JEPA should preserve not only how uncertain the future is, but which distinct futures constitute that uncertainty, how they form coherent trajectories, and how those beliefs compose through time.

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Publication record

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First public release: 2026-08-21 · Indexed by Pub-AI: 2026-10-14 UTC

preprint

MDN-VJEPA: Multimodal Probabilistic Joint-Embedding World Models

Yongchao Huang

Preprint posted: 2026-08-21 · Original record ↗

arxiv
2610.13956
Explicit source versions (1)
  • v1 · 2026-08-21
  1. Preprint available

    Source date: 2026-08-21 · First detected: 2026-10-25 UTC · Historical baseline

    Source evidence (1)
Abstract · arxiv

Joint-Embedding Predictive Architectures (JEPAs) learn world models by predicting future representations rather than reconstructing observations. Variational JEPA (VJEPA) gives this prediction probabilistic semantics and permits flexible conditional predictive families. We propose MDN-VJEPA, a multimodal probabilistic JEPA that instantiates the latent predictor as a mixture density network (MDN), representing future states with a Gaussian mixture whose components encode alternative futures, their probabilities, and within-mode uncertainty. For sequential prediction, we address two additional structural requirements: multi-modal futures should remain temporally coherent across a trajectory, and predictive beliefs should remain consistent when propagated to the same horizon through different temporal path compositions, as motivated by the Chapman--Kolmogorov equation. Together, these considerations define a three-level hierarchy of multimodal prediction, coherent multimodal trajectories, and compositionally consistent multimodal dynamics. Controlled experiments show that MDN-VJEPA closely recovers known branching predictive laws, that retaining the complete multimodal belief rather than its conditional mean can lead to materially different and substantially better planning decisions under branching futures, and that trajectory-level coupling and distributional consistency improve temporal coherence and multi-horizon agreement. These results support a simple principle: a probabilistic JEPA should preserve not only how uncertain the future is, but which distinct futures constitute that uncertainty, how they form coherent trajectories, and how those beliefs compose through time.