Quantum spreading of a self-gravitating wave-packet in singularity free gravity

Spreading of wave packets, Uncertainty Relations and the de Broglie Frequency

The spreading of quantum mechanical wave packets is studied in two cases. Firstly we look at the time behavior of the packet width of a free particle confined in the observable Universe. Secondly, by imposing the conservation of the time average of the packet width of a particle driven by a harmonic oscillator potential, we find a zero-point energy which frequency is the de Broglie frequency.

Quantum solitonic wave-packet of a meso-scopic system in singularity free gravity

In this paper we will discuss how to localise a quantum wave-packet due to self-gravitating meso-scopic object by taking into account gravitational self-interaction in the Schrödinger equation beyond General Relativity. In particular, we will study soliton-like solutions in infinite derivative ghost free theories of gravity, which resolves the gravitational $1/r$ singularity in the potential. We will show a unique feature that the quantum spread of such a gravitational system is larger than that of the Newtonian gravity, therefore enabling us a window of opportunity to test classical and quant…

Approximations for the free evolution of self-gravitating quantum particles

The evolution of the centre-of-mass wave-function for a mesoscopic particle according to the Schrödinger-Newton equation can be approximated by a harmonic potential, if the wave-function is narrow compared to the size of the particle. It was noticed by Colin et al. [Phys. Rev. A, 93, 062102 (2016)] that, in the regime where self-gravitational effects are weak, intermediate and wider wave-functions may be approximated by a harmonic potential as well, but with a width dependent coupling, leading to a time evolution that is determined only by a differential equation for the width of a Gaussian wa…

On free fall of quantum matter

We propose an approach that allows to systematically take into account gravity in quantum particle physics. It is based on quantum field theory and the general principle of relativity. These are used to build a model for quantum particles in curved spacetime. We compute by its means a deviation from a classical geodesic in the Earth's gravitational field. This shows that free fall depends on quantum-matter properties. Specifically, we find that the free-fall universality and the wave-packet spreading are mutually exclusive phenomena. We then estimate the Eötvös parameter for a pair of atoms fr…

On the Classical Limit of Spin Network Gravity: Two Conjectures

Estimates are given of the time scales which govern spreading of a coherent state wave packet. The estimates, based on dimensional analysis, suggest that spreading should be small for coherent states with average angular momentum of order 100 or larger. It is conjectured that in the classical limit, terms in the Hamiltonian which add a new vertex will be suppressed, compared to terms which modify the existing spin network without changing the number of vertices.

中微子退相干与强等效原理的违反

Neutrino decoherence and violation of the strong equivalence principle

该研究在扩展引力理论框架下分析中微子高斯波包动力学、味振荡阻尼及退相干效应，发现强等效原理违反的量化参数会调制波包扩散，或在未来中微子实验中产生可测效应。