2009/12/02 by Giuseppe Castagnoli, Castagnoli, Giuseppe · 1 voice · 1 citation
Computer Science · Physics and Astronomy · #Algorithm #Artificial intelligence #Computation #Computer science #FOS: Physical sciences #Oracle #Projection (relational algebra) #Quantum #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum Mechanics and Applications #Quantum Physics (quant-ph) #Quantum algorithm #Quantum computer #Theoretical computer science #Variety (cybernetics) #quant-ph
paper · pdf · doi:10.48550/arxiv.0912.0401
published in arXiv (Cornell University) (Cornell University) · 15 pages, resubmitted to Phys Rev A, the 50% rule is now related to backdating to before running the algorithm a time-symmetric part of the final projection on the solution.
openalex publication_date 2009/12/02 · arxiv published 2009/12/02 · arxiv created 2010/04/05 · arxiv updated 2010/04/05 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
In former work, we showed that a quantum algorithm requires the number of operations (oracle's queries) of a classical algorithm that knows in advance 50% of the information that specifies the solution of the problem. We gave a preliminary theoretical justification of this "50% rule" and checked that the rule holds for a variety of quantum algorithms. Now, we make explicit the information about the solution available to the algorithm throughout the computation. The final projection on the solution becomes acquisition of the knowledge of the solution on the part of the algorithm. Backdating to before running the algorithm a time-symmetric part of this projection, feeds back to the input of the computation 50% of the information acquired by reading the solution.