Details

Autor(en) / Beteiligte

• Gillis, Edward Joseph

Titel

A Lorentz invariant, microphysical theory of wave function collapse

Ort / Verlag

ProQuest Dissertations & Theses

Erscheinungsjahr

1990

Quelle

ProQuest Dissertations & Theses A&I

Beschreibungen/Notizen

• Quantum measurements typically involve a sudden change in the state of the measured system. Prior to a measurement, the state of the system can be represented as the superposition of several state vectors. Subsequent to it, the system is in a single one of these states. This nonlocal, probabilistic change in the quantum state is usually called wave-function collapse. It is not consistent with evolution of the system according to the dynamical equations of quantum theory. In order to incorporate the description of wave-function collapse into a consistent physical theory, it is first necessary to identify the specific types of microscopic processes with which wave-function collapse is associated. Measurements require the establishment of correlations between states of the measured system and states of the apparatus. According to the (linear) dynamical equations of quantum theory, this typically implies that the state of the system-plus-apparatus evolves from a product state to a nonproduct state. I hypothesize that it is this sort of evolution that is responsible for wave-function collapse. Specifically, I postulate that whenever an interaction between two elementary particles changes their joint wave function from a product state to a nonproduct state, there is, in addition to the ordinary, linear evolution, a small jump toward either the interacting component of the wave function, or toward its noninteracting, orthogonal complement. Wave-function collapse occurs as the result of a very large number of very small jumps. The hypothesis thus yields the projection postulate, and it implies the probability interpretation as well. It explains why the wave function collapses to the desired basis, rather than to some other basis, and it preserves the normalization of the state vector. It also makes specific experimental predictions. The hypothesis can also be extended to handle multiple measurements in a relativistically invariant fashion. This is done by ordering the individual jumps associated with correlating interactions that are timelike related according to their temporal ordering. Series of measurements that are spacelike separated are then ordered according to the norm of the wave-function component being measured (smallest first), without regard to their temporal ordering in any reference frame.