The first edition of CL4SM, a session at the ELLIS UnConference 2026 on enforcing physical laws and other known constraints in machine learning models of scientific and engineering systems.
About
Machine learning methods have been increasingly used to model, simulate, and forecast scientific and engineering systems due to their performance and lower computational costs. However, even when a model has a good fit to the data it can be scientifically wrong: creating or destroying mass and energy, producing negative concentrations, violating boundary conditions, or drifting into unphysical regimes over predictions outside the training time horizon. These violations compromise the trust in a learnt model, hindering its adoption in simulation pipelines, digital twins, or decision making.
The problem of incorporating prior knowledge or constraints into these methods has sparked interest in the literature, and different approaches exist: soft penalty terms, projection, correction and differentiable optimisation layers, and hard architectural guarantees. However, several limitations exist when choosing between them, at a cost in accuracy, training stability, and compute.
In this session, we promote discussion across machine learning methods, from new approaches to successful applications in real-world systems. The focus is on promoting transparency, trust, and security in machine learning methods.
Topics of Interest
Soft constraint enforcement
Penalty and augmented-loss formulations, and their optimisation pathologies.
Hard enforcement by construction
Conservation-by-design, structure-preserving architectures, monotone/positive/convex parametrisations.
Projection & correction
Projection and correction methods, differentiable optimisation layers, and multi-stage training schemes.
Constraints from governing equations
Conservation laws, symmetries, boundary and initial conditions, thermodynamic consistency.
Stability & safety
Stability and safety of learned dynamical models; invariant sets, certified behaviour for safety-critical deployment.
Probabilistic constraints
Constrained generative models, calibrated and physically consistent uncertainty quantification.
Guarantees vs. accuracy vs. cost
Theory, benchmarks, and rigorous comparisons across enforcement strategies.
Applications in science & engineering
Climate and environment (conservation-constrained emulators, physically consistent downscaling), fluids and engineering (thermodynamically consistent constitutive models, stable surrogates), and energy and industrial systems (power grids, batteries, cyber-physical systems).
Call for Contributions
We invite submissions on all aspects of constrained learning for scientific modelling: methods that enforce conservation laws, symmetries, boundary conditions, stability, or other prior knowledge in machine learning models, theory and benchmarks that compare enforcement strategies, and applications in science and engineering. We welcome work from machine learning, applied mathematics, optimisation, and the natural and engineering sciences.
Submissions are limited to 2 pages (including references) and fall into one of two categories:
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Ongoing work
New methods, theoretical results, benchmarks, or applications that are still in progress. Early-stage ideas and negative results that shed light on the trade-offs between accuracy, guarantees, and cost are explicitly welcome. Accepted abstracts are presented as a talk (8 min + 2 min Q&A) and a poster.
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Tutorials, demos, software libraries & datasets
Descriptions of interactive tutorials or demos (such as Jupyter notebooks), libraries and packages, or datasets that show how constrained learning methods, architectures, or papers are implemented in practice. Accepted contributions are presented as a 2-minute lightning pitch and a demo during the poster session.
Recently published papers
We also welcome work recently published at top-tier conferences and journals such as JMLR, JAIR, MLJ, PAMI, IJCAI, NeurIPS, ICLR, AISTATS, and ICML. Please state the original venue and upload the PDF of the published paper. Accepted papers are presented as a talk (8 min + 2 min Q&A) and a poster.
Review process
Submissions are reviewed single-blind by the Program Committee, with at least two reviews and one meta-review each. Since the number of talk slots is limited, some contributions may be presented as posters only.
How to submit
Prepare your contribution as a PDF using the PMLR template, and submit it via Microsoft CMT by October 30, 2026 (23:59 AoE). The session is non-archival. If you have any questions, contact the organisers.
Important Dates
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Oct 1 Call for contributionsSubmissions open
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Oct 30 AoE Submission deadlineUnder review
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Nov 12 Notification to authorsProgramme assembly
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Nov 27 Final programmeCountdown to session
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Dec 8 Session
Schedule
December 8, 2026. The start time will be announced; times below are relative to the start of the session.
| Time | Activity |
|---|---|
| 0:00–0:05 |
Opening remarks by the organisers
|
| 0:05–0:35 |
Invited keynote: TBA
25 min talk + 5 min Q&A
|
| 0:35–1:35 |
Contributed talks
6 × 10 min (8 min + 2 min Q&A)
|
| 1:35–1:50 |
Lightning poster & demo pitches
5–7 × 2 min
|
| 1:50–2:00 |
Open discussion & invitation to the poster session
|
| 2:00 |
Poster & demo session
End of the day
|
Venue
Palais des Congrès de Paris
2 Place de la Porte Maillot, 75017 Paris
Open in map
The ELLIS UnConference takes place in Paris just before NeurIPS 2026.
Invited Speaker
The keynote speaker will be announced soon.
Organisers
Cecília Coelho
Institute for Artificial Intelligence (HSU-AI), Helmut Schmidt University, Hamburg, Germany
Andrzej Dulny
Chair of Data Science, University of Würzburg, Germany
Fernanda Costa
Centre of Mathematics, University of Minho, Portugal
Ricardo Baptista
Department of Statistical Sciences and Vector Institute, University of Toronto, Canada
Luís Ferrás
Department of Mechanical Engineering, University of Porto, Portugal
Oliver Niggemann
Institute for Artificial Intelligence (HSU-AI), Helmut Schmidt University, Hamburg, Germany
Program Committee
🚧 This list is still under construction.
- George StepaniantsCalifornia Institute of Technology, USA
- Artur LiebertHSU-AI, Helmut Schmidt University, Hamburg, Germany
- Christian WittkeHSU-AI, Helmut Schmidt University, Hamburg, Germany
- Robin KurthHSU-AI, Helmut Schmidt University, Hamburg, Germany
- Simon HentschelCAIDAS, University of Würzburg, Germany
- Florian GallusserCAIDAS, University of Würzburg, Germany







