[Paper Review] Gravity Resonance Spectroscopy and Einstein-Cartan Gravity

H. Abele, A. N. Ivanov+3 more|arXiv (Cornell University)|Jan 1, 2015

Atomic and Subatomic Physics Research2 references3 citations

TL;DR

This paper proposes gravity resonance spectroscopy (GRS) using ultracold neutrons in Earth's gravitational field to probe quantum effects in gravity, particularly torsion in Einstein-Cartan gravity. By measuring resonant transitions between quantized gravitational states, the experiment provides a sensitive test of torsion coupling, offering new constraints on spin-torsion interactions in a quantum gravity framework.

ABSTRACT

The qBounce experiment offers a new way of looking at gravitation based on quantum interference. An ultracold neutron is reflected in well-defined quantum states in the gravitypotential of the Earth by a mirror, which allows to apply the concept of gravity resonance spectroscopy (GRS). This experiment with neutrons gives access to all gravity parametersas the dependences on distance, mass, curvature, energy-momentum as well as on torsion. Here, we concentrate on torsion.

Motivation & Objective

• To investigate the influence of torsion on quantum states of ultracold neutrons in Earth's gravitational field.
• To test predictions of Einstein-Cartan gravity using quantum interference in a gravitational potential.
• To develop a high-precision experimental method for probing gravity parameters, including torsion, via neutron quantum states.
• To establish gravity resonance spectroscopy as a tool for detecting weak spin-torsion interactions.

Proposed method

• Utilizes the qBounce experiment to trap ultracold neutrons in the gravitational potential above a mirror.
• Measures resonant transitions between quantized gravitational energy levels using radiofrequency fields.
• Analyzes shifts in resonance frequencies to infer coupling to torsion fields in Einstein-Cartan gravity.
• Applies quantum mechanical formalism to model neutron states in a curved spacetime with torsion.
• Compares observed transition frequencies with theoretical predictions including torsion contributions.
• Uses interference patterns and energy-level quantization to extract sensitivity to gravity parameters beyond mass and curvature.

Experimental results

Research questions

• RQ1 Can gravity resonance spectroscopy detect torsion effects in the gravitational interaction of ultracold neutrons?
• RQ2 How does torsion in Einstein-Cartan gravity modify the energy levels of neutrons in Earth's gravitational field?
• RQ3 What is the sensitivity of the qBounce experiment to spin-torsion coupling in quantum gravity?
• RQ4 To what extent can torsion be constrained using quantum interference in gravitational states?
• RQ5 How do quantum states in a gravitational potential respond to spacetime torsion?

Key findings

• The qBounce experiment demonstrates sensitivity to torsion through shifts in neutron energy levels due to spin-torsion coupling.
• Resonance spectroscopy in the gravitational field enables probing of gravity parameters including torsion with high precision.
• Theoretical modeling shows that torsion induces measurable shifts in quantum state transitions, detectable in ultracold neutron experiments.
• The method provides a new, model-independent way to test Einstein-Cartan gravity using quantum systems.
• The experiment sets new bounds on the strength of torsion coupling by analyzing deviations in resonance frequencies.
• Quantum interference in gravitational states allows for the detection of weak torsion effects not accessible by classical gravity experiments.