Necessary condition for incompatibility of observables in general probabilistic theories
: Filippov SN, Heinosaari T, Leppajarvi L
Publisher: AMER PHYSICAL SOC
: 2017
: Physical Review A
: PHYSICAL REVIEW A
: PHYS REV A
: ARTN 032127
: 95
: 3
: 8
: 2469-9926
: 2469-9934
DOI: https://doi.org/10.1103/PhysRevA.95.032127
: https://research.utu.fi/converis/portal/detail/Publication/22377757
We quantify the intrinsic noise content of an observable in a general probabilistic theory and derive a noise content inequality for incompatible observables. We apply the derived inequality to standard quantum theory, the quantum theory of processes, and polytope state spaces. The noise content for positive operator-valued measures takes a particularly simple form and equals the sum of minimal eigenvalues of all the effects. We illustrate our findings with a number of examples including the introduced notion of reverse observables.