Towards a Physics Foundation Model
Florian Wiesner, Matthias Wessling, Stephen Baek

TL;DR
This paper introduces GPhyT, a transformer-based physics model trained on diverse data that can simulate multiple physical phenomena, generalize to unseen systems, and outperform specialized models, paving the way for a universal Physics Foundation Model.
Contribution
The paper presents GPhyT, the first large-scale transformer model capable of learning and generalizing physical dynamics across multiple domains without retraining.
Findings
GPhyT outperforms specialized models by over 7x in multiple physics tasks.
GPhyT demonstrates zero-shot generalization to unseen physical systems.
GPhyT provides more stable long-term predictions through long-horizon rollouts.
Abstract
Foundation models have revolutionized natural language processing through a ``train once, deploy anywhere'' paradigm, where a single pre-trained model adapts to countless downstream tasks without retraining. Access to a Physics Foundation Model (PFM) would be transformative - democratizing access to high-fidelity simulations, accelerating scientific discovery, and eliminating the need for specialized solver development. Yet current physics-aware machine learning approaches remain fundamentally limited to single, narrow domains and require retraining for each new system. We present the General Physics Transformer (GPhyT), trained on 1.8 TB of diverse simulation data, that demonstrates foundation model capabilities are achievable for physics. Our key insight is that transformers can learn to infer governing dynamics from context, enabling a single model to simulate fluid-solid…
Peer Reviews
Decision·Submitted to ICLR 2026
1. A Compelling New Paradigm: The primary strength is the successful application of the in-context learning paradigm to physics simulation. The idea that a model can infer dynamics from a prompt of prior states , rather than being explicitly told the equations, is a significant shift from specialized solvers like PINNs or most Neural Operators. 2. Strong Generalization Results: The paper's most convincing result is the zero-shot generalization to unseen boundary conditions (Table 2). The model a
1. Weak Baseline Comparisons: The "up to 29x" performance gain is against a standard FNO (from 2020) and a standard UNet. These architectures were not designed for the multi-physics, in-context inference task this paper proposes. A stronger comparison would involve more recent, advanced operator architectures. This overstates the "breakthrough" on known physics (Q1). 2. Major Unsolved Limitations: The authors correctly identify the key limitations, but they are severe. The model is 2D onlyand, m
The evaluations (at least those provided in the appendix) are detailed. The ablation for the direct next-step prediction in appendix 6.4 is nice and addresses a question that I would have asked, given that many other models do this. It is interesting to see that the separation of differentiation and integration provides a substantial improvement on predictive performance. It is encouraging to see that GPhyT at 9M parameters outperforms 100M+ parameter UNet and FNO; this indicates that the GP
It would be really nice to see one of Tables 3, 4, or 5 in the main text, to get a better understanding of the performance of all the models for each of the different datasets, rather than just an average. I would like to see stronger baselines, and in particular ones which are designed for multiple physics like McCabe (2024), which is mentioned a few times in this paper as a relevant work.
This is a really well presented and written paper and dataset contributions are extremely valuable. Strengths included: 1. The paper is well written and engaging. Figures are easy to read and convey the appropriate information to support the text. 2. The motivation is clear. The problem and some previous attempts at addressing them are laid out as solid motivation. 3. The dataset contributions are excellent. They highlight a weakness of a public dataset and provide well-reasoned data to fill in
While the paper shows significant promise and enginuity, the current draft requires heavy re-writes and additional experiments. The paper makes strong claims, but often provides no supporting evidence. There appears to be the core of a strong paper here, but the submission isn't at a point I can recommend acceptance right now. Critical 1. The critical issue right now is that the claims and experimental evidence are far apart. The most prominent claim in the submission is excellent zero shot p
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Taxonomy
TopicsMachine Learning in Materials Science · Model Reduction and Neural Networks · Quantum many-body systems
