A simple gravitational self-decoherence model

Abstract

One of the most significant debates of our time is whether our macroscopic world (i) naturally emerges from quantum mechanics or (ii) requires new physics. We argue for the latter and propose a simple gravitational self-decoherence mechanism. For this purpose, we postulate the existence of a Heisenberg cut such that particles with masses $m$ much smaller and larger than a critical mass $M_{\mathrm{C}}$ (of the order of the Planck mass $M_{\mathrm{P}}$) would be necessarily treated according to quantum and classical rules, respectively. Our effective model is designed to capture the new physics that free quantum particles would experience as their masses approach $M_{\mathrm{C}}$. The purity loss for free quantum particles is evaluated and shown to be highly inefficient for quantum particles with $m\ll M_{\mathrm{C}}$ but very effective for those with $m\sim M_{\mathrm{C}}$. The physical picture behind it is that coherence would (easily) leak from heavy enough particles to (non-observable) spacetime quantum degrees of freedom. Finally, we contextualize our proposal with state-of-the-art experiments and show how it can be tested in a future Stern-Gerlach-like experiment.

14 pages (final version), 15 figures

References in corpus (25)

• Models of Wave-function Collapse, Underlying Theories, and Experimental Tests
• Testing the limits of quantum mechanical superpositions
• Observation of Radiation Pressure Shot Noise on a Macroscopic Object
• Effective Field Theory Approach to Gravitationally Induced Decoherence
• Gravitational Decoherence
• Schrödinger cat states of a 16-microgram mechanical oscillator
• Underground test of gravity-related wave function collapse
• A Master Equation for Gravitational Decoherence: Probing the Textures of Spacetime
• Shortcomings in the Understanding of Why Cosmological Perturbations Look Classical
• Realization of a complete Stern-Gerlach interferometer: Towards a test of quantum gravity
• Approaching the motional ground state of a 10 kg object
• Constructing Nano-Object Quantum Superpositions with a Stern-Gerlach Interferometer
• Testing the foundations of quantum physics in space Interferometric and non-interferometric tests with Large Particles
• Quantum Theory of the Classical: Einselection, Envariance, Quantum Darwinism and Extantons
• Understanding nature from experimental observations: a theory independent test for gravitational decoherence
• Quantum signatures of black hole mass superpositions
• Centre-of-mass motion in multi-particle Schroedinger-Newton dynamics
• Gravitational Decoherence: A Thematic Overview
• Critical review of prevailing explanations for the emergence of classicality in cosmology
• Testing quantum superpositions of the gravitational field with Bose-Einstein condensates
• Gravitational decoherence: a general non relativistic model
• The number of fundamental constants from a spacetime-based perspective
• Disfavoring the Schroedinger-Newton equation
• Self-gravitational dephasing of quasi-classical Stern-Gerlach trajectories
• Probing the Schroedinger-Newton equation in a Stern-Gerlach interferometer

Cited by in corpus (2)

• Quantum internal vibrations in macroscopic systems with classical centers of mass
• Will we ever quantize the centers of mass of heavy systems? A case for a Heisenberg cut in quantum mechanics