Quantum gravity phenomenology: from atoms to the cosmos

Abstract

Quantum Theory and General Relativity are two of the most successful theories of Nature in their respective regimes. In situations where effects from both are non-negligible, the regime of Quantum Gravity emerges. Many theories, such as String Theory, Loop Quantum Gravity and Doubly Special Relativity, attempt to address the high-energy regime of Quantum Gravity. The structures of such theories suggest the existence of a minimum measurable length. This in turn modifies the Heisenberg Uncertainty Principle, to the so-called Generalized Uncertainty Principle (GUP). In this work, GUP is used to construct phenomenological models, which can be used to verify the existence of a minimum measurable length. Specifically, in Earth-based experiments, the magnetometer experiment and Bose-Einstein condensation are considered, and in cosmology, explanations of the baryon asymmetry in the Universe and the EDGES anomaly are provided. Furthermore, a novel conceptual approach to Quantum Gravity, namely the Quantum Equivalence Principle, is explored.