Comment on "Dynamical reduction models" by A. Bassi and G.C. Ghirardi (arXiv:quant-ph/0302164)

Parameter Independence and Outcome Independence in Dynamical Collapse Theories

Ghirardi, Grassi, Butterfield, and Fleming have previously argued that two distinct formulations of dynamical reduction (GRW) theories have distinct non-local properties: one (the "non-linear" formulation) violates Parameter Independence while the other (the "linear + cooking" formulation) violates Outcome Independence. The claim is then that, since theories violating Outcome Independence are compatible with relativity in a way that theories violating Parameter Independence are not, the "linear + cooking" dynamical reduction theories hold the key to reconciling quantum non-locality with relati…

Comment on "Quantum mechanics for non-inertial observers"

In a recent paper (arXiv:1701.04298 [quant-ph]) Toroš, Großardt and Bassi claim that the potential necessary to support a composite particle in a gravitational field must necessarily cancel the relativistic coupling between internal and external degrees of freedom. As such a coupling is responsible for the gravitational redshift measured in numerous experiments, the above statement is clearly incorrect. We identify the simple mistake in the paper responsible for the incorrect claim.

Quantum open systems and turbulence

We show that the problem of non conservation of energy found in the spontaneous localization model developed by Ghirardi, Rimini and Weber is very similar to the inconsistency between the stochastic models for turbulence and the Navier-Stokes equation. This sort of analogy may be useful in the development of both areas.

Atomic "bomb testing": the Elitzur-Vaidman experiment violates the Leggett-Garg inequality

Elitzur and Vaidman have proposed a measurement scheme that, based on the quantum superposition principle, allows one to detect the presence of an object --- in a dramatic scenario, a bomb --- without interacting with it. It was pointed out by Ghirardi that this interaction-free measurement scheme can be put in direct relation with falsification tests of the macro-realistic worldview. Here we have implemented the "bomb test" with a single atom trapped in a spin-dependent optical lattice to show explicitly a violation of the Leggett-Garg inequality --- a quantitative criterion fulfilled by macr…

Remarks on a Proposed Super-Kamiokande Test for Quantum Gravity Induced Decoherence Effects

Lisi, Marrone, and Montanino have recently proposed a test for quantum gravity induced decoherence effects in neutrino oscillations observed at Super-Kamiokande. We comment here that their equations have the same qualitative form as the energy conserving objective state vector reduction equations discussed by a number of authors. However, using the Planckian parameter value proposed to explain state vector reduction leads to a neutrino oscillation effect many orders of magnitude smaller than would be detectable at Super-Kamiokande. Similar estimates hold for the Ghirardi, Rimini, and Weber spo…

Spontaneous collapse: a solution to the measurement problem and a source of the decay in mesonic systems

Dynamical reduction models propose a solution to the measurement problem in quantum mechanics: the collapse of the wave function becomes a physical process. We compute the predictions to decaying and Dynamical reduction models propose a solution to the measurement problem in quantum mechanics: the collapse of the wave function becomes a physical process. We compute the predictions to decaying and flavor--oscillating neutral mesons for the two most promising collapse models, the QMUPL (Quantum Mechanics with Universal Position Localization) model and the mass-proportional CSL (Continuous Sponta…

一种新型自发坍缩模型的提案

A proposal for a new kind of spontaneous collapse model

本文提出一种以固定时空坐标坍缩点为核心的非相对论自发坍缩模型，兼具 GRW 与 CSL 特征，可处理不可分辨粒子、导出 CSL 主方程、解决测量问题并纳入牛顿引力。

Poisson stochastic master equation unravellings and the measurement problem: a quantum stochastic calculus perspective

The paper studies a class of quantum stochastic differential equations, modeling an interaction of a system with its environment in the quantum noise approximation. The space representing quantum noise is the symmetric Fock space over L^2(R_+). Using the isomorphism of this space with the space of square-integrable functionals of the Poisson process, the equations can be represented as classical stochastic differential equations, driven by Poisson processes. This leads to a discontinuous dynamical state reduction which we compare to the Ghirardi-Rimini-Weber model. A purely quantum object, the…