PIRSA:09110036

Why Does Nature Like the Square Root of Negative One?

Wootters, W. (2009). Why Does Nature Like the Square Root of Negative One? . Perimeter Institute. https://pirsa.org/09110036

Wootters, William. Why Does Nature Like the Square Root of Negative One? . Perimeter Institute, Nov. 18, 2009, https://pirsa.org/09110036 

          @misc{ pirsa_PIRSA:09110036,
            doi = {10.48660/09110036},
            url = {https://pirsa.org/09110036},
            author = {Wootters, William},
            keywords = {Quantum Information},
            language = {en},
            title = {Why Does Nature Like the Square Root of Negative One? },
            publisher = {Perimeter Institute},
            year = {2009},
            month = {nov},
            note = {PIRSA:09110036 see, \url{https://pirsa.org}}
          }

William Wootters Williams College

Talk numberPIRSA:09110036
DOI10.48660/09110036
Collection
Talk Type Scientific Series
Subject

Abstract

Is there a theory yet to be discovered that underlies quantum theory and explains its structure? If there is such a theory, one of the features it will have to explain is the central role of complex numbers as probability amplitudes. In this talk I explore the physical meaning of the statement “probability amplitudes are complex” by comparing ordinary complex-vector- space quantum theory with the real-vector-space theory having the same basic structure. Specifically, I discuss three questions that bring out qualitative differences between the two theories: (i) Is information about a preparation expressed optimally in the outcomes of a measurement? (ii) Are multipartite states locally accessible? (iii) Is entanglement “monogamous”?