Article

Naturalness in an emergent analogue spacetime

International School for Advanced Studies and INFN, Via Beirut 2-4, 34014 Trieste, Italy.
Physical Review Letters (Impact Factor: 7.73). 05/2006; 96(15):151301. DOI: 10.1103/PhysRevLett.96.151301
Source: arXiv

ABSTRACT Effective field theories (EFTs) have been widely used as a framework in order to place constraints on the Planck suppressed Lorentz violations predicted by various models of quantum gravity. There are, however, technical problems in the EFT framework when it comes to ensuring that small Lorentz violations remain small--this is the essence of the "naturalness" problem. Herein we present an "emergent" spacetime model, based on the "analogue gravity" program, by investigating a specific condensed-matter system. 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 explicitly avoids the naturalness problem, and makes specific suggestions regarding how to construct a physically reasonable quantum gravity phenomenology.

Full-text

Available from: Matt Visser, May 29, 2015
0 Followers
 · 
120 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We offer a critical assessment of some generic features of various current approaches to the construction of a theory of quantum gravity. We argue that there is a need for further conceptual clarifications before such an enterprise can be launched in a truly well-grounded setting, and that one of the guiding principles that can be viewed as part of the reasons for successes of the past theoretical developments is the identification of unspeakables --- concepts that should not only play no role in the formulation of the theories, but ones that the formalism of the theory itself should prevent from ever being spoken about.
    International Journal of Modern Physics D 03/2008; 17(3-4):425-443. DOI:10.1142/S0218271808012103 · 1.42 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We develop a new formalism for the description of the condensates of cold Fermi atoms whose speed of sound can be tuned with the aid of a narrow Feshbach resonance. We use this to look for spontaneous phonon creation that mimics spontaneous particle creation in curved space-time in Friedmann-Robertson-Walker and other model universes.
    Journal of Physics Condensed Matter 09/2013; 25(40):404211. DOI:10.1088/0953-8984/25/40/404211 · 2.22 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The explanation about the origin of cosmic structure, provided by the standard inflationary paradigm, is not fully satisfactory, as has been argued in [A. Perez, H. Sahlmann, and D. Sudarsky, Class. Quant. Grav. 23 (2006) 2317]. The central point of that work is that something important is missing in our understanding of the origin of the seeds of cosmic structure, as is evidenced by the fact that, in the standard accounts, the inhomogeneity and anisotropy of our universe seems to emerge from an exactly homogeneous and isotropic initial state through processes that can not break those symmetries. We review here the problem and the proposal to address this shortcoming in terms of dynamical collapse of the original vacuum of the inflaton field, and indicate how it might be connected to other issues facing the study of the quantum/gravity interface.
    International Journal of Modern Physics D 05/2011; 20(5):821-838. DOI:10.1142/S0218271811019165 · 1.42 Impact Factor