2021/04/19 by Paola Boito, Roberto Grena · 1 voice
Computer Science · Mathematics · Physics and Astronomy · #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum-Dot Cellular Automata #cs.NA #math.NA #quant-ph
paper · pdf · doi:10.1093/comnet/cnab038
published as Journal of Complex Networks, Volume 9, Issue 6, December 2021, cnab038
arxiv created 2021/04/19 · openalex publication_date 2021/10/07 · arxiv updated 2021/11/15 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
In this work we introduce, test and discuss three quantum methods for computing hub and authority centrality scores in directed networks. The methods are based on unitary, continuous-time quantum walks; the construction of a suitable Hermitian Hamiltonian is achieved by performing a quantum walk on the associated bipartite graph. Two methods, called CQAu and CQAw, use the same evolution operator, inspired by the classical HITS algorithm, but with different initial states; the computation of hub and authority scores is performed simultaneously. The third method, called CQG and inspired by classical PageRank, requires instead two separate runs with different evolution operators, one for hub and one for authority scores. The methods are tested on several directed graphs with different sizes and properties; a comparison with other well-established ranking algorithms is provided. CQAw emerges as the most reliable of the three methods and yields rankings that are largely compatible with results from HITS, although CQAu and CQG also present interesting features and potential for applications.