Quantum theory of measurement: Wave function collapse, decoherence and related interference phenomena

Jeffrey Alan Barrett

Abstract Moving to more subtle experiments, we consider how the standard formulation of quantum mechanics predicts and explains interference phenomena. Tracking the conditions under which one observes interference phenomena leads to the notion of quantum decoherence. We see why one must sharply distinguish between collapse phenomena and decoherence phenomena on the standard formulation of quantum mechanics. While collapses explain determinate measurement records, environmental decoherence just produces more complex, entangled states where the physical systems involved lack ordinary physical properties. We characterize the quantum-mechanical wave function as both an element of a Hilbert space and a complex-valued function over a configuration space. We also discuss how the wave function is interpreted in the standard theory.

Mirjana Božić, Z. Marić

Mikio Namiki

Jianan Wang

In this paper, the physical explanation of all quantum phenomena such as wave function, wave function collapse, wave-particle duality, single-electron double-slit interference, uncertainty relation, tunneling effect and quantum entanglement is given by using the new etheric theory, and a new uncertainty relation which is consistent with the latest experimental results is given.

Rochelle Forrester

Anthony James Donnelly

We propose a double-slit photon interference experiment conducted across three gravitational conditions (1g, ~0g, 0.16g) to test whether gravitational field strength modulates wave function collapse behaviour. This proposal does not assume wave function collapse is ontologically real; it tests whether effective collapse behaviour—operationalised as interference fringe visibility and decoherence rate—varies with gravitational context. A secondary experiment introduces information accessibility as a variable, testing whether the causal availability of which-path information affects collapse statistics differently across gravitational conditions. Null results would place strong upper bounds on gravitationally induced collapse models, constraining Penrose-type theories. Positive results would provide the first direct experimental evidence for a gravitational component in quantum state reduction. Keywords: wave function collapse, quantum decoherence, gravity, Penrose objective reduction, measurement problem, double-slit experiment, microgravity