Hellwig, K.-E. Relative entropy of states in a two \(q\)-bit system. (English) Zbl 1071.81507 Doebner, H.-D. (ed.) et al., Quantum theory and symmetries. Proceedings of the international symposium held in Goslar, Germany, July 18–22, 1999. Singapore: World Scientific (ISBN 981-02-4237-9). 412-417 (2000). MSC: 81P15 82B10 94A17 PDF BibTeX XML Cite \textit{K. E. Hellwig}, in: Quantum theory and symmetries. Proceedings of the international symposium held in Goslar, Germany, July 18--22, 1999. Singapore: World Scientific. 412--417 (2000; Zbl 1071.81507)
Hellwig, K.-E. Quantum measurements and information theory. (English) Zbl 0866.46048 Gielerak, R. (ed.) et al., Quantum groups and related topics. Proceedings of the first Max Born symposium, Wojnowice Castle, Wrocław, Poland, September 27-29, 1991. Dordrecht: Kluwer Academic Publishers. Math. Phys. Stud. 13, 211-221 (1992). Reviewer: W.Slowikowski (Aarhus) MSC: 46N50 81P15 PDF BibTeX XML Cite \textit{K. E. Hellwig}, Math. Phys. Stud. 13, 211--221 (1992; Zbl 0866.46048)
Hellwig, K.-E. Conditional expectations and duals of instruments. (English) Zbl 0537.60033 Interpretations and foundations of quantum theory, Proc. Conf., Marburg 1979, 113-124 (1981). Reviewer: H.Cycon MSC: 60G20 46L51 46L53 46L54 81P20 60J99 PDF BibTeX XML