PIRSA:18020086

Modifying the quantum measurement postulates (and more)

APA

Galley, T. (2018). Modifying the quantum measurement postulates (and more). Perimeter Institute. https://pirsa.org/18020086

MLA

Galley, Thomas. Modifying the quantum measurement postulates (and more). Perimeter Institute, Feb. 08, 2018, https://pirsa.org/18020086

BibTex

          @misc{ pirsa_18020086,
            doi = {10.48660/18020086},
            url = {https://pirsa.org/18020086},
            author = {Galley, Thomas},
            keywords = {Quantum Foundations},
            language = {en},
            title = {Modifying the quantum measurement postulates (and more)},
            publisher = {Perimeter Institute},
            year = {2018},
            month = {feb},
            note = {PIRSA:18020086 see, \url{https://pirsa.org}}
          }
          

Abstract

In this talk I show how to systematically classify all possible alternatives to the measurement postulates of quantum theory. All alternative measurement postulates are in correspondence with a representation of the unitary group. I will discuss composite systems in these alternative theories and show that they violate two operational properties: purification and local tomography. This shows that one can derive the measurement postulates of quantum theory from either of these properties. I will discuss the relevance of this result to the field of general probabilistic theories. In a second part of the talk I will discuss work in progress and directions for future research. I will show how to generalise the framework used to theories which have different pure states and dynamics than quantum theory. I will discuss two types of theories which can be studied in this framework: Grassmannian theories (same dynamical group and different pure states to quantum theory) and non-linear modifications to the Schrodinger equation (same pure states and different dynamical group).