2013/11/26 by P. B. Lerner, Lerner, Peter B.
Computer Science · Physics and Astronomy · #Advanced Algebra and Logic #Computability, Logic, AI Algorithms #FOS: Physical sciences #Mathematical Physics (math-ph) #Quantum Mechanics and Applications #Quantum Physics (quant-ph)
paper · pdf · doi:10.48550/arxiv.1311.6781
openalex publication_date 2013/11/26 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The widely considered assertion is that the unitarity of quantum mechanical evolution assures the preservation of information. It is even promoted in popular literature as an established fact. (Susskind, 2008) Yet, a simple chain of reasoning demonstrates that: 1) almost any evolutionary operator can be well approximated by a degenerate (finite-rank) operator and 2) one needs an eternity to retrieve information exactly from a nonstationary quantum state and to distinguish between arbitrary unitary operator and its finite-dimensional approximations.