Analogue model for quantum gravity phenomenology

The so-called 'analogue models' use condensed matter systems (typically hydrodynamic) to set up an 'effective metric' and to model curved-space quantum field theory in a physical system where all the microscopic degrees of freedom are well understood. Known analogue models typically lead to massless minimally coupled scalar fields. We present an extended 'analogue spacetime' programme by investigating a condensed-matter system-in and beyond the hydrodynamic limit-that is in principle capable of simulating the massive Klein-Gordon equation in a curved spacetime. Since many elementary particles have mass, this is an essential step in building realistic analogue models, and an essential first step towards simulating quantum gravity phenomenology. Specifically, we consider the class of two-component BECs subject to laser-induced transitions between the components, and we show that this model is an example for Lorentz invariance violation due to ultraviolet physics. Furthermore, our model suggests constraints on quantum gravity phenomenology in terms of the 'naturalness problem' and 'universality issue'.