Matrix variances with projections

Dénes Petz, Géza Tóth

Research output: Contribution to journalArticle

3 Citations (Scopus)


The quantum variance of a self-adjoint operator depends on a density matrix whose particular example is a pure state (formulated by a projection). A general variance can be obtained from certain variances of pure states. This is very different from the probabilistic case. All rights reserved

Original languageEnglish
Pages (from-to)683-688
Number of pages6
JournalActa Scientiarum Mathematicarum
Issue number3-4
Publication statusPublished - Dec 1 2012


  • Density matrix
  • Projection
  • Pure state
  • Variance

ASJC Scopus subject areas

  • Analysis
  • Applied Mathematics

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