arXiv Machine Learning

Sparse Sum-of-Squares Layers for Certified Learning

The paper introduces Sparse Sum-of-Squares (SOS) Layers, a new type of differentiable layer that reuses the sparse structure of forward semidefinite programming (SDP) solves during backpropagation. By avoiding dense certificate construction, the method achieves up to 2.7× faster warm‑call times and reduces memory usage from 160 GiB to 1.7 GiB on large problems. Experiments demonstrate its effectiveness across sparse polynomial certification, control, combinatorial relaxations, robotics, oscillator chains, and pose‑graph synchronization, achieving zero certified violations on unseen instances with far fewer optimization solves than finite‑difference approaches.

arXiv Machine Learning
Oct 16

SUPN: Shallow Universal Polynomial Networks for Efficient Function Approximation

The paper introduces Shallow Universal Polynomial Networks (SUPNs), a single‑hidden‑layer architecture that replaces standard activations with learnable multivariate polynomials, thereby increasing expressivity per unit. SUPNs achieve universal approximation by either widening the network or increasing polynomial complexity, and the authors prove convergence rates and quasi‑optimal parameter choices. Empirical tests across a wide range of smooth, nonsmooth, and discontinuous functions in up to ten dimensions show that SUPNs often outperform deep neural networks and Kolmogorov‑Arnold networks in accuracy and variability while requiring fewer parameters and lower training cost.

By Zachary Morrow, Michael Penwarden, Brian Chen, Aurya Javeed, Akil Narayan, John D. Jakeman
arXiv Machine Learning
Oct 12

BLOKS: Scaling Kernel Solvers with Sketched Block Preconditioning

BLOKS is a Conjugate Gradient-based solver for Nyström‑sketched Kernel Ridge Regression that introduces a novel preconditioner combining block Jacobi approximation with sketching. This preconditioner’s memory cost is independent of dataset size and model parameters, enabling scaling to large models while maintaining GPU acceleration. Experiments on standard large‑scale datasets show BLOKS achieves accuracy comparable to or better than state‑of‑the‑art kernel solvers with favorable time/memory complexity.

By Giordano Vitale, Giacomo Meanti, Marco Rando, Blanca Ayuso de Dios, Lorenzo Rosasco