arXiv AI

Readable Is Not Steerable: Pre-Registered Tests of Physical Structure in Learned Fluid Representations

The paper reports three pre‑registered studies on 2D Navier‑Stokes flow that examine whether self‑supervised models organize their latent spaces around physical fluid quantities. In Study 1, a joint‑embedding predictive architecture (JEPA) fails to outperform an untrained network in capturing fluid dynamics, while a JEPA trained on non‑physical dynamics and a static invariance model perform equally well or better. Study 2 shows that plain autoencoders make enstrophy prominent in their slowest latent directions, and adding VICReg reduces this prominence but improves linear decodability. Study 3 constructs steerable latent directions (“dials”) via routing; a loudness dial is found in all eight trained models and a shape dial in three of five seeds, though neither control shows a shape dial. Across all studies, the content of a latent and what can be controlled through it diverge, and exploratory experiments reveal that supervised spectral‑shape directions do not affect the output when steered.

Hugging Face Trending Papers
Jun 10

Sparse probes and murky physics: a case study of interpretability challenges in a foundation model for continuum dynamics

Generative AI emulators are increasingly used in scientific domains where we already have strong theory, benchmarks, and physical intuition. This raises a central evaluation and interpretability question: when a foundation-style model can reproduce known continuum dynamics, what internal mechanism supports that behavior, is the internal behaviour consistent with known physics, and how does it relate to where the emulator succeeds or fails?

arXiv Machine Learning
Oct 5

Drive vs. Decay: On the Training Dynamics of Joint-Embedding Predictive Architectures

The paper introduces a stability theory for Joint-Embedding Predictive Architectures (JEPAs), showing that training dynamics involve a driving force and a decay effect that determine representation collapse. By linearising the gradient flow, the authors derive a per‑mode stability ratio that separates data‑side and predictor‑side contributions, predicting a phase boundary confirmed across 800 configurations. Using this insight, they propose ResidualPred, a transformer predictor that biases attention toward the identity at initialization, improving representation rank and downstream accuracy on tabular and image benchmarks.

By Jos\'e Lucas De Melo Costa, Seong Woo Ahn, Fabrice Popineau, Arpad Rimmel, Bich-Li\^en Doan
arXiv Machine Learning
Oct 23

RheOPT: Few-Shot Non-Newtonian Flow Prediction via Newtonian Pretraining of RheOFormer

RheOPT is a transformer-based neural operator that first pretrains on inexpensive Newtonian fluid simulations and then fine‑tunes on a small set of non‑Newtonian samples. By reusing geometry‑conditioned transport structures rather than the Newtonian constitutive response, RheOPT achieves accurate few‑shot predictions for complex fluids such as Giesekus, Oldroyd‑B, and Bingham in a contraction channel and for oscillatory wake flows behind a triangular obstacle. The approach demonstrates that Newtonian pretraining can match or surpass models trained from scratch with four times as many non‑Newtonian samples, especially when using reversible instance normalization.

By Maedeh Saberi, Amir Barati Farimani, Safa Jamali
arXiv Machine Learning
Jul 30

What Can Latent World Models Know? Physical Parameter Identifiability in Multimodal Predictive Representations

arXiv:2607. 27017v1 Announce Type: new Abstract: A central premise of latent world models is that predicting the future forces a representation to internalize the physics of its environment.

By Kaizhen Tan (New York University, Carnegie Mellon University), Xin Xu (Carnegie Mellon University), Siru Tao (Carnegie Mellon University), Hanzhe Hong (Carnegie Mellon University), Yang Feng (Columbia University), Heqing Du (Columbia University)
arXiv Machine Learning
Oct 8

LayerRoPE: Dynamic Depth-wise Magnitude & Angular Superposition

LayerRoPE introduces a depth‑wise magnitude and angular superposition mechanism that replaces per‑layer normalization gains with a single shared vector and depth‑conditioned scalars, reducing parameters and computational cost. Across 16 pre‑trained large language models and a 100B+ token model ladder, LayerRoPE outperforms traditional Pre‑, Post‑, and Peri‑Norm schemes, achieving comparable or better performance with significantly less compute and improved convergence up to 512 layers. The method demonstrates that widening the residual stream, rather than shrinking it, enhances depth stability and learning‑rate sensitivity, and it transfers effectively to latent and vision transformer architectures.

By Shikhar Srivastava, Christopher Kanan