Symplectic latent dynamics prevent rollout contraction in visual world models

LeHami uses Hamiltonian structure to preserve latent phase-space volume while improving long-horizon motion prediction on visual pendulum tasks.

Academic
Romina Yalovetzky · Randall Balestriero · Yann LeCun

Courant Institute, New York University · Brown University · AMI Labs

Research Digest··3 min read
Yalovetzky, Balestriero and LeCun replace an unconstrained JEPA predictor with a learned, action-conditioned Hamiltonian flow over position-like and momentum-like latent variables.

The authors developed LeHami, a joint-embedding predictive architecture whose latent state is divided into a canonical pair, q and p, analogous to position and momentum.

Why this paper

From Courant Institute, New York University and 2 others · Released code

In one line

A symplectic Hamiltonian flow as the JEPA predictor preserves latent phase-space volume and substantially improves long-horizon velocity prediction on pendulum environments.

What it released

Code

What we could check

  • ✓Code link in the paper (github.com)
  • ·No weights link found
  • ·No dataset link found
  • ·No compute details found
  • ✓Limitations stated by the authors (2 noted)
  • ·No benchmark numbers found

Observed from the paper text and links we have. Absence here means we did not find it, not that it does not exist.

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Research Digest

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