Degree-Optimized Cumulative Polynomial Kolmogorov-Arnold Networks
Mathew Vanherreweghe, Lirandë Pira, Patrick Rebentrost
TL;DR
CP-KAN addresses the challenge of learning high-dimensional functions with limited data by integrating Chebyshev-polynomial activations into a Kolmogorov-Arnold network and reframing per-neuron degree selection as a QUBO optimization. This reduces the combinatorial burden to a single optimization per layer, enabling adaptive complexity without prohibitive cost. Empirically, CP-KAN achieves competitive regression performance with far fewer parameters, demonstrates robustness to input scaling, and gains theoretical grounding in financial time-series mean-reversion via Chebyshev expansions. The work highlights a principled direction for efficient neural architectures that blend classical approximation theory with discrete optimization, with potential extensions to online adaptation and quantum annealing.
Abstract
We introduce cumulative polynomial Kolmogorov-Arnold networks (CP-KAN), a neural architecture combining Chebyshev polynomial basis functions and quadratic unconstrained binary optimization (QUBO). Our primary contribution involves reformulating the degree selection problem as a QUBO task, reducing the complexity from $O(D^N)$ to a single optimization step per layer. This approach enables efficient degree selection across neurons while maintaining computational tractability. The architecture performs well in regression tasks with limited data, showing good robustness to input scales and natural regularization properties from its polynomial basis. Additionally, theoretical analysis establishes connections between CP-KAN's performance and properties of financial time series. Our empirical validation across multiple domains demonstrates competitive performance compared to several traditional architectures tested, especially in scenarios where data efficiency and numerical stability are important. Our implementation, including strategies for managing computational overhead in larger networks is available in Ref.~\citep{cpkan_implementation}.
