Authors

Arjan van der Schaft

Abstract

The structure of continuous Hopfield networks is revisited from a system-theoretic point of view. After adopting a novel electrical network interpretation involving nonlinear capacitors, it is shown that Hopfield networks admit a port-Hamiltonian formulation provided an extra passivity condition is satisfied. Subsequently it is shown that any Hopfield network can be represented as a gradient system, with Riemannian metric given by the inverse of the Hessian matrix of the total energy stored in the nonlinear capacitors. On the other hand, the well-known ‘energy’ function employed by Hopfield turns out to be the dissipation potential of the gradient system, and this potential is shown to satisfy a dissipation inequality that can be used for analysis and interconnection.

Citation

  • Journal: IEEE Transactions on Automatic Control
  • Year: 2026
  • Volume:
  • Issue:
  • Pages: 1–4
  • Publisher: Institute of Electrical and Electronics Engineers (IEEE)
  • DOI: 10.1109/tac.2026.3740658

BibTeX

@article{van_der_Schaft_2026,
  title={{Hopfield neural networks as port-Hamiltonian and gradient systems}},
  ISSN={2334-3303},
  DOI={10.1109/tac.2026.3740658},
  journal={IEEE Transactions on Automatic Control},
  publisher={Institute of Electrical and Electronics Engineers (IEEE)},
  author={van der Schaft, Arjan},
  year={2026},
  pages={1--4}
}

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