Interaction Between Macroscopic Quantum Systems and Gravity

The gravitational force has the distinctive feature of interacting universally with all forms of energy. It dominates at large scales and is well described by general relativity. In the latter theory, gravity is interpreted as a direct affection of the geometry of the spacetime: masses generate spacetime curvature, which in turn determines the motion of the masses. In contrast to quantum mechanics, spacetime in general relativity plays a dynamical role and it is not a rigid background structure, with the time acting as a parameter.

Experimentally, quantum field theory works very well at the microscopic scale, while general relativity gives a consistent description of the large-scale dynamics, where gravitation dominates. However, quantum macroscopic systems exist in nature, like superconductors and superfluids, so that it could be possible to observe or speculate about a possible interplay of the two theories.

This Research Topic studies the possible mutual interplay between the gravitational field and materials in the superconducting state. More generally, we are interested in effects originating from the presence of "coherent" matter states (like superfluids or Bose-Einstein condensates) interacting with the local gravitational field.

Our target is the study of the interplay between a quantum macrosystem and the local gravitational field, investigating possible, observable effects not explained in terms of classical physics. In particular, we focus on the possibility for quantum macrosystems in a coherent state to produce local alterations on the gravitational field in which they are immersed. It would also be desirable to describe an appropriate experimental setting for the proposed interaction, where it would be possible to verify qualitatively and quantitatively the predictions of the new theories.

Another possibility is to consider the effect of quantum fluctuations of the gravitational field with a possible, anomalous coupling to a macroscopic condensate wavefunction, exploring existing dualities between different theories (holographic models).

The aim of the current Research Topic is to cover promising, recent, and novel research trends in the described interaction between macroscopic quantum systems and the local gravitational field. Areas to be covered in the Research Topic may include, but are not limited to:

- superconductors and gravitational drag;

- gravitomagnetism and gravito-Maxwell formalism;

- superfluids/gravity interplay;

- semiclassical dynamics of condensates;

- gauge-gravity dualities;

- AdS/CFT correspondence;

- quantum gravity.