Input convex neural networks as surrogates in mathematical optimisation

arXiv:2608.09707 2026 Architecture 1 ideas extracted · analyzed Sep 1, 2026

What the math gives to ML

The paper’s main transferable asset is not a new activation but the deliberate enforcement of input convexity, which turns a neural surrogate into an object with exploitable global geometry. Nonnegative hidden-to-hidden weights preserve convexity while retaining expressive ReLU piecewise-linear behavior, and the resulting network can be embedded in optimization through linear epigraph constraints rather than binary variables in favorable minimization settings. This suggests using ICNNs as optimization-aware MLPs whenever the target response is known or suspected to be convex, and using their convex structure as an inductive bias rather than merely adding a post hoc convexity penalty. The strongest practical test is a matched-capacity comparison against a ReLU MLP on surrogate prediction and downstream solve time.

Ideas from this paper

Mechanism confirmed, baseline not beaten 2026

LP-Embedded Input-Convex MLP

Replace a standard ReLU surrogate with an input convex neural network whose hidden-to-hidden weights are constrained to be nonnegative. The network remains piecewise linear and expressive, but its convexity allows downstream minimization to use continuous ReLU epigraph constraints instead of binary activation variables, potentially eliminating the integrality bottleneck of neural optimization.

Useful8/10
Difficulty5/10
Novelty5/10
Paper: Input convex neural networks as surrogates in mathematical optimisation arXiv:2608.09707