Convexification of mixed-integer quadratic optimization via decision diagrams

arXiv:2608.22815 2026 Architecture 2 ideas extracted · analyzed Aug 29, 2026

What the math gives to ML

The paper gives a constructive way to optimize binary activation patterns coupled to continuous variables under a quadratic objective, by representing partial assignments with decision-diagram states and merging assignments that induce the same boundary-conditioned quadratic residual. The transferable asset is not generic mixed-integer optimization itself, but the state-compression principle: for tree-structured or inverse-tree-structured interactions, a potentially exponential collection of masks can be represented by a small dynamic program. This suggests exact structured gating or expert-selection layers for neural networks whose redundancy, communication, or activation-cost model is sparse in a graph. The approximate-boundary result further suggests linear-size routing and pruning procedures with an explicit controllable optimization gap.

Ideas from this paper

Mechanism failed 2026

Tree-Structured Exact Expert Router

Replace independent top-k expert selection with a decision-diagram router that optimizes a quadratic surrogate over binary expert activations and continuous assignment weights. When expert redundancy or communication costs form a tree, partial routing decisions are merged whenever they have the same separator state, turning exponentially many candidate masks into a dynamic program over a small number of graph cuts.

Useful7/10
Difficulty7/10
Novelty8/10
Paper: Convexification of mixed-integer quadratic optimization via decision diagrams arXiv:2608.22815
✓✓ Beats tuned baseline 2026

Boundary-Compressed Approximate Pruning

Use an approximate decision diagram to select a structured subset of neurons, channels, attention heads, or attention edges when their quadratic interactions are sparse or inverse-sparse. Merge states that agree on a local interaction boundary and accept a tunable epsilon loss in the pruning objective, obtaining a representation whose size is linear in model width for fixed accuracy tolerance.

Useful6/10
Difficulty6/10
Novelty7/10
Paper: Convexification of mixed-integer quadratic optimization via decision diagrams arXiv:2608.22815