arXiv AI

Neural networks for spectral optimization

arXiv Machine Learning
2d ago

Learning Spectrally Optimised Mesh-Free Discretisations

The paper introduces Spectrally Optimised Neural Discretisations (SpeND), a mesh‑free framework that learns discretisation weights from local stencil geometry on unstructured point clouds. By embedding discrete moment conditions into the network architecture, SpeND guarantees polynomial consistency and allows the weights to be optimised for spectral accuracy over a chosen wavenumber band, using an unsupervised Fourier‑mode loss. The resulting operators are PDE‑agnostic, perform well on Poisson, Burgers, and Navier–Stokes equations, and can reduce wall‑clock time by 3–20× compared to existing mesh‑free methods at the same accuracy.

By Lucas Gerken Starepravo, Henry Broadley, Steven Lind, Jack R. C. King
arXiv Machine Learning
Aug 11

The Spectral Neuron

arXiv:2608. 08003v1 Announce Type: cross Abstract: As machine learned models increase in complexity and expressive power, features of simpler models, such as interpretability and control over the shape of the modeled function are lost.

By Alex Shtoff
arXiv AI
Jul 7

Learning to Discover Iterative Spectral Algorithms

arXiv:2602. 09530v2 Announce Type: replace-cross Abstract: We introduce AutoSpec, a neural network framework for discovering iterative spectral algorithms for large-scale numerical linear algebra and numerical optimization.

By Zihang Liu, Oleg Balabanov, Yaoqing Yang, Michael W. Mahoney
arXiv Machine Learning
Sep 3

Learning Spectral-Like Mesh-Free Discretisations

The paper introduces Spectral-like Neural Discretisation (SpeND), a mesh‑free method that learns stencil weights via a neural network to approximate the modal response of a spectral operator across a specified band of wavenumbers. By projecting the network output onto the space of polynomial‑consistent weights, SpeND ensures exact consistency while minimizing dispersion and dissipation errors in a self‑supervised, physics‑agnostic manner. Experiments on disordered 2‑D node sets demonstrate that the learned fourth‑order operator matches the exact spectral response over a wider band than traditional LABFM or structured‑grid finite differences, and retains fourth‑order convergence upon refinement.

By Lucas Gerken Starepravo, Henry Broadley, Steven Lind, Jack R. C. King
arXiv Machine Learning
Sep 22

Helix-FNO: Spectral-Domain Operator Learning Coupled with a High-Fidelity Mechanistic Model for Fast Surrogate Simulation

Helix‑FNO is a teacher‑student framework that couples a 32‑state mechanistic model with a Fourier neural operator to learn the full solution operator for full‑scale treatment processes. The teacher generates a high‑fidelity dataset via Latin‑hypercube sampling and active learning, while the student learns in the spectral domain, enabling generalisation across varying influent profiles, controls, and plant layouts. The resulting operator achieves millisecond inference, three orders of magnitude faster than the mechanistic teacher, and is evaluated against physics‑informed and data‑driven surrogates on accuracy, dataset efficiency, and latency, positioning it on a speed‑accuracy Pareto front.

By Jiabao Zhao, Chuwei Wang, Jinxi Yang