Recurrent Equilibrium Networks: Flexible Dynamic Models with Guaranteed Stability and Robustness
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Abstract (arXiv)
This paper introduces recurrent equilibrium networks (RENs), a new class of nonlinear dynamical models for applications in machine learning, system identification and control. The new model class admits ``built in'' behavioural guarantees of stability and robustness. All models in the proposed class are contracting -- a strong form of nonlinear stability -- and models can satisfy prescribed incremental integral quadratic constraints (IQC), including Lipschitz bounds and incremental passivity. RENs are otherwise very flexible: they can represent all stable linear systems, all previously-known sets of contracting recurrent neural networks and echo state networks, all deep feedforward neural networks, and all stable Wiener/Hammerstein models, and can approximate all fading-memory and contracting nonlinear systems. RENs are parameterized directly by a vector in RN, i.e. stability and robustness are ensured without parameter constraints, which simplifies learning since HLgeneric methods for unconstrained optimization such as stochastic gradient descent and its variants can be used. The performance and robustness of the new model set is evaluated on benchmark nonlinear system identification problems, and the paper also presents applications in data-driven nonlinear observer design and control with stability guarantees.
Key facts. Cited by 43 papers in the map (data through 7 Oct 2026). Builds on 34 of its 96 references that are in the map. First posted on arXiv 13 Apr 2021.
Builds on
34 of 96 references.
References · 34
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Citing papers per year: 2021: 3; 2022: 1; 2023: 10; 2024: 12; 2025: 9; 2026: 8.
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- 2025R2DN: Scalable Parameterization of Contracting and Lipschitz Recurrent Deep Networks1 Apr 2025
- 2025L2RU: a Structured State Space Model with prescribed L2-bound31 Mar 2025
- 2024Contractive Dynamical Imitation Policies for Efficient Out-of-Sample Recovery10 Dec 2024
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- 2024Convex neural network synthesis for robustness in the 1-norm29 May 2024
- 2024On Dissipativity of Cross-Entropy Loss in Training ResNets29 May 2024
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- 2024Mapping back and forth between model predictive control and neural networks18 Apr 2024
- 2024Synthesizing Neural Network Controllers with Closed-Loop Dissipativity Guarantees10 Apr 2024
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- 2024State space representations of the Roesser type for convolutional layers18 Mar 2024
- 2024Learning to optimize with convergence guarantees using nonlinear system theory14 Mar 2024
- 2024Monotone, Bi-Lipschitz, and Polyak-Lojasiewicz Networks2 Feb 2024
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- 2023Convolutional Neural Networks as 2-D systems6 Mar 2023
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- 2026Data-driven discrete-time deep recurrent neural network-based modeling for dissipative systems23 Sep 2026
- 2026Scalable Incremental Robustness Analysis of Neural Network Feedback Systems18 Sep 2026
- 2026Can a Dynamic Internal Field Govern a Transformer's Cognition? Certifiability, not Superiority, in Homeostatic Compute Control25 Aug 2026
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- 2026Stability-Preserving Online Adaptation of Neural Closed-loop Maps23 Mar 2026
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- 2025Circuit realization and hardware linearization of monotone operator equilibrium networks17 Sep 2025
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- 2025React to Surprises: Stable-by-Design Neural Feedback Control and the Youla-REN2 Jun 2025
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