arXiv Machine Learning

Identifiable World Models from Pretrained Diffusion Representations

The paper demonstrates that a frozen pretrained diffusion model can be endowed with identifiable latent coordinates via a lightweight alignment map called Contrastive Diffusion Alignment (ConDA). By leveraging auxiliary-variable nonlinear ICA guarantees, ConDA aligns diffusion latents so that the resulting representation recovers latent dynamical states up to permutation and componentwise invertible transformations, preserves the underlying structural causal model, and simplifies lagged graph recovery. Experiments on physical and robotic video systems show that ConDA, especially under TCL and GCL assumptions, achieves near-perfect state recovery and accurate lagged graph reconstruction, even in simulated falling-body and bipedal robot scenarios.

arXiv AI
Sep 25

RD-JEPA: Predictive latent pretraining for few-trajectory transfer across reaction--diffusion equations

RD‑JEPA is a joint‑embedding predictive architecture designed for self‑supervised pretraining on reaction‑diffusion trajectories. The model is pretrained on five parameterized systems and then adapted to three held‑out systems that were not seen during pretraining. Using as few as one, five, or ten complete trajectories from a held‑out system, RD‑JEPA outperforms five supervised surrogate baselines, an independently trained control that removes the trajectory‑dependent predictive latent pathway, and an architecture‑matched model trained from scratch, achieving lower mean relative discrete β field error and mean absolute spatial first‑difference error across various output resolutions, forecast horizons, and adaptation trajectory choices.

By Chenhao Si, Ming Yan
arXiv AI
Sep 15

Freeze, Share, Shrink: Rethinking the Action Backbone in Diffusion Policies

The paper argues that diffusion-based action policies can use a frozen, observation‑free backbone as a reusable trajectory prior, with task adaptation handled entirely by the conditioning pathway. By pretraining a general action head on forward‑kinematics data and then freezing it, the authors show that a single backbone can match or outperform normally trained models on MimicGen and LIBERO. Their experiments reveal that a small 5 M‑parameter MLP backbone can rival large U‑Net and transformer backbones, indicating that action backbones are often over‑parameterized and that image‑style architectures may not be the best fit for low‑dimensional action generation.

By Jian Zhou, Sihao Lin, Shuai Fu, Zerui Li, Gengze Zhou, Qi WU
arXiv AI
Jun 3

Coupled Local and Global World Models for Efficient First Order RL

arXiv:2602. 06219v2 Announce Type: replace-cross Abstract: World models offer a promising avenue for more faithfully capturing complex dynamics, including contacts and non-rigidity, as well as complex sensory information, such as visual perception, in situations where standard simulators struggle.

By Joseph Amigo, Rooholla Khorrambakht, Nicolas Mansard, Ludovic Righetti
arXiv Computer Vision
Sep 24

AWM-VLA: AlignedWorld Modeling for Efficient and Explainable Vision-Language-Action Policies

AWM‑VLA introduces a unified framework that embeds aligned world modeling directly into a diffusion‑transformer vision‑language‑action policy. By adding learnable future tokens aligned with vision‑language embeddings of future observations, the policy can anticipate long‑term consequences while generating actions. The method extends this with an object‑centric alignment objective and a principled weighting scheme, achieving up to 21% higher success rates on RoboCasa and humanoid tabletop benchmarks and producing object‑centric rationales preferred by human raters in 83% of cases.

By An Lanji, Dawei Liu, Jin Li, Haoran Xu, Mei Chen, Yu Tian
arXiv Machine Learning
Oct 8

DSReg: Provably Recovering Individual World Latents without Reconstruction

The paper introduces DSReg, a method that provably recovers individual world latent variables without relying on reconstruction, decoders, or labels. It leverages a Structural Diversity condition—distinct dependency footprints of different latents—to achieve full identifiability up to signed permutation. DSReg can be applied post hoc to any linearly identified representation, preserving dense prediction while improving latent recovery across synthetic and real-world experiments.

By Yujia Zheng, David Klindt, Randall Balestriero, Bernhard Sch\"olkopf