titleQQWorld: Quantile-Quantile Matching for World Model Regularization
authorsZhoushun Yu, Xiaoyu Hu, Xiangyu Xu
date2026-07-30
venuearXiv (preprint, not peer reviewed)
idarXiv:2607.28415
upvotes20 (Hugging Face Daily Papers, 2026-11-01)
linksabs pdf hf
primerWorld models
abstractLatent world models enable efficient planning by predicting future states in a compact representation space, but their performance depends critically on the quality of the learned latent distribution. LeWorldModel (LeWM) regularizes its latents toward an isotropic Gaussian using the Epps-Pulley (EP) objective. We show that the corrective gradients of EP rapidly vanish for isolated tail samples, leaving heavy-tailed deviations insufficiently controlled. To address this limitation, we propose QQWorld, which replaces EP with a quantile-quantile matching objective that directly aligns projected latent samples with rank-matched Gaussian quantiles, thereby maintaining effective corrective gradients in the tails. We further develop cross-batch QQ, which enlarges the effective ranking pool using detached samples from previous batches, and characterize its bias-variance trade-off. Across four control environments, QQWorld effectively improves the average planning success rate of LeWM, while consistently yielding better Gaussian alignment and thinner latent tails.

cite

@misc{yu2026qqworld,
  title={QQWorld: Quantile-Quantile Matching for World Model Regularization},
  author={Zhoushun Yu and Xiaoyu Hu and Xiangyu Xu},
  year={2026},
  eprint={2607.28415},
  archivePrefix={arXiv},
  url={https://arxiv.org/abs/2607.28415}
}