Quantum Gravity

Overview

Quantum gravity is a field of theoretical physics that seeks to unify two fundamental theories of physics: quantum mechanics and general relativity. Quantum mechanics describes the behavior of matter and energy at the smallest scales, while general relativity describes the gravitational interactions between massive objects and the geometry of spacetime. The challenge arises when trying to reconcile these two theories because they have different mathematical frameworks and conceptual foundations. General relativity is a classical theory, treating gravity as a curvature of spacetime, while quantum mechanics is a quantum theory, dealing with discrete energy levels and wave-particle duality. The need for a theory of quantum gravity arises in extreme conditions, such as near the Big Bang or inside black holes, where both quantum effects and gravity are significant. At these scales, the discrepancies between quantum mechanics and general relativity become apparent, and a more comprehensive theory is required to understand the nature of spacetime and gravity.

Our interests

In our group, we are interested in asking whether the gravitational field is in fact a quantum object at all. Analogously to the Casimir effect in quantum electrodynamics, a gravitational Casimir effect has been predicted which is many orders of magnitude weaker than its quantum electrodynamical cousin. If this effect could be measured however, this would provide strong evidence for a quantum character of the gravitational field.

Selected publications

1. James Q. Quach, “Spin gravitational resonance and graviton detection.” Physical Review D 93, no. 10 (2016): 104048.
2. James Q. Quach, “Gravitational casimir effect.” Physical Review Letters 114, no. 8 (2015): 081104.