A comparison between models of gravity induced decoherence of the wavefunction

7th International Workshop DICE2014 Spacetime – Matter – Quantum Mechanics

物理学;力学

Bera, S.^1 ; Donadi, S.^2,3 ; Lochan, K.^4 ; Singh, Tp^1

Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai

400 005, India^1

Department of Physics, University of Trieste, Strada Costiera 11, Trieste

34151, Italy^2

Istituto Nazionale di Fisica Nucleare, Trieste Section, Via Valerio 2, Trieste

34127, Italy^3

IUCAA, Pune University Campus, Post Bag 4, Ganeshkhind, Pune

411 007, India^4

关键词: Classical gravity;    Coherence lengths;    Gravitational fields;    Measurement process;    Noise correlation;    Similar models;    Space time geometry;    Two-point correlation;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/626/1/012040/pdf
DOI  :  10.1088/1742-6596/626/1/012040

学科分类：力学，机械学

来源: IOP

【 摘 要 】

It has already been suggested that quantum theory needs to be reformulated or modified in order to explain the measurement process and the successive collapse of the wave- function. However, there are also models of another type which keep quantum theory intact and instead modify the classical gravity by introducing stochasticity to it. These models suggest that there is a fluctuation in the background gravitational field which eventually results in the decoherence of the wavefunction. These fluctuations limit the precision with which one can measure the properties of a spacetime geometry with a quantum probe. Two similar models along this line have been suggested by Karolyhazy (K-model) and Diósi(D-model). They are based upon apparently different spacetime bounds. The results obtained for the coherence length are also somewhat different. In this article, we show that, given certain conditions apply, the minimal spacetime bounds in these two models are equivalent. We also derive the two-point correlation for the fluctuation potential in K-model which turns out to be non-white, unlike in D-model, where the corresponding correlation is white noise in time. In our opinion, this is the origin of discrepancy in the predictions of the two models. We argue that the noise correlation cannot be determined uniquely from a given spacetime bound.