2 research outputs found
On the limits of quantum theory: contextuality and the quantum-classical cut
This paper is based on four assumptions: 1. Physical reality is made of
linearly behaving components combined in non-linear ways. 2. Higher level
behaviour emerges from this lower level structure. 3. The way the lower level
elements behaves depends on the context in which they are imbedded. 4. Quantum
theory applies to the lower level entities. An implication is that higher level
effective laws, based in the outcomes of non-linear combinations of lower level
linear interactions, will generically not be unitary; hence the applicability
of quantum theory at higher levels is strictly limited. This leads to the view
that both state vector preparation and the quantum measurement process are
crucially based in top-down causal effects, and helps provide criteria for the
Heisenberg cut that challenge some views on Schroedinger's cat.Comment: 65 pages, 10 diagrams. Revised in response to referee comments; to
appear in Annals of Physic