PUBO Formulation for MST and Application to Optimum-Path Forest

Fuente: arXiv
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Bibliographic Details
Main Authors: Pexe, Guilherme E. L., Rattighieri, Lucas A. M., Passos, Leandro A., Jodas, Danilo S., Rodrigues, Douglas, Fanchini, Felipe F., Papa, João P., Costa, Kelton A. P.
Format: Preprint
Published: 2026
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author Pexe, Guilherme E. L.
Rattighieri, Lucas A. M.
Passos, Leandro A.
Jodas, Danilo S.
Rodrigues, Douglas
Fanchini, Felipe F.
Papa, João P.
Costa, Kelton A. P.
author_facet Pexe, Guilherme E. L.
Rattighieri, Lucas A. M.
Passos, Leandro A.
Jodas, Danilo S.
Rodrigues, Douglas
Fanchini, Felipe F.
Papa, João P.
Costa, Kelton A. P.
contents The Optimum-Path Forest is a graph-based framework for designing classifiers that exploit inter-sample connectivity. A particular variant constructs decision boundaries based on prototypes computed by a Minimum Spanning Tree (MST) over the training data, which might become prohibitive for large-scale datasets. In this context, Quantum Machine Learning has emerged as a promising approach to overcome the high computational burden of combinatorial problems. We propose a quantum-inspired approach for prototype selection in OPF classifiers by reformulating the MST problem as a Polynomial Unconstrained Binary Optimization (PUBO) task and further employing the Feedback-Based Quantum Optimization (FALQON) algorithm for Hamiltonian minimization. The PUBO formulation reduces the need for qubits and eliminates the need for auxiliary variables, thereby addressing scalability constraints in current quantum hardware. Experiments on real-world datasets demonstrate that the FALQON-optimized MST achieves accuracies comparable to those of the classical Prim's algorithm while maintaining prototype quality. While FALQON occasionally reached local minima, it did not significantly impact the accuracy of the prototype selection process.
format Preprint
id arxiv_https___arxiv_org_abs_2605_20637
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle PUBO Formulation for MST and Application to Optimum-Path Forest
Pexe, Guilherme E. L.
Rattighieri, Lucas A. M.
Passos, Leandro A.
Jodas, Danilo S.
Rodrigues, Douglas
Fanchini, Felipe F.
Papa, João P.
Costa, Kelton A. P.
Quantum Physics
The Optimum-Path Forest is a graph-based framework for designing classifiers that exploit inter-sample connectivity. A particular variant constructs decision boundaries based on prototypes computed by a Minimum Spanning Tree (MST) over the training data, which might become prohibitive for large-scale datasets. In this context, Quantum Machine Learning has emerged as a promising approach to overcome the high computational burden of combinatorial problems. We propose a quantum-inspired approach for prototype selection in OPF classifiers by reformulating the MST problem as a Polynomial Unconstrained Binary Optimization (PUBO) task and further employing the Feedback-Based Quantum Optimization (FALQON) algorithm for Hamiltonian minimization. The PUBO formulation reduces the need for qubits and eliminates the need for auxiliary variables, thereby addressing scalability constraints in current quantum hardware. Experiments on real-world datasets demonstrate that the FALQON-optimized MST achieves accuracies comparable to those of the classical Prim's algorithm while maintaining prototype quality. While FALQON occasionally reached local minima, it did not significantly impact the accuracy of the prototype selection process.
title PUBO Formulation for MST and Application to Optimum-Path Forest
topic Quantum Physics
url https://arxiv.org/abs/2605.20637