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No Free Lunch for Quantum Machine Learning

Quantum Physics 2020-04-01 v1

Abstract

The ultimate limits for the quantum machine learning of quantum data are investigated by obtaining a generalisation of the celebrated No Free Lunch (NFL) theorem. We find a lower bound on the quantum risk (the probability that a trained hypothesis is incorrect when presented with a random input) of a quantum learning algorithm trained via pairs of input and output states when averaged over training pairs and unitaries. The bound is illustrated using a recently introduced QNN architecture.

Keywords

Cite

@article{arxiv.2003.14103,
  title  = {No Free Lunch for Quantum Machine Learning},
  author = {Kyle Poland and Kerstin Beer and Tobias J. Osborne},
  journal= {arXiv preprint arXiv:2003.14103},
  year   = {2020}
}

Comments

8 pages, 1 figure, appendix on Haar-measure integral calculations via tensor networks

R2 v1 2026-06-23T14:33:32.325Z