How to Measure the Quantum Measure. In memory of David Ritz Finkelstein
Abstract
The historiesbased framework of Quantum Measure Theory assigns a generalized probability or measure μ( E) to every (suitably regular) set E of histories. Even though μ( E) cannot in general be interpreted as the expectation value of a selfadjoint operator (or POVM), we describe an arrangement which makes it possible to determine μ( E) experimentally for any desired E. Taking, for simplicity, the system in question to be a particle passing through a series of SternGerlach devices or beamsplitters, we show how to couple a set of ancillas to it, and then to perform on them a suitable unitary transformation followed by a final measurement, such that the probability of a final outcome of "yes" is related to μ( E) by a known factor of proportionality. Finally, we discuss in what sense a positive outcome of the final measurement should count as a minimally disturbing verification that the microscopic event E actually happened.
 Publication:

International Journal of Theoretical Physics
 Pub Date:
 January 2017
 DOI:
 10.1007/s107730163181x
 arXiv:
 arXiv:1610.02087
 Bibcode:
 2017IJTP...56..232F
 Keywords:

 Quantum measure theory;
 Coupling ancillas;
 Quantum Physics;
 General Relativity and Quantum Cosmology
 EPrint:
 Int J Theor Phys (2017) 56: 232258