Predictive description of Planck-scale-induced spacetime fuzziness

Abstract

Several approaches to the quantum-gravity problem predict that spacetime should be "fuzzy", but have been so far unable to provide a crisp physical characterization of this notion. An intuitive picture of spacetime fuzziness has been proposed on the basis of semi-heuristic arguments, and in particular involves an irreducible Planck-scale contribution to the uncertainty of the energy of a particle. These arguments also inspired a rather active phenomenological programme looking for blurring of images of distant astrophysical sources that would result from such energy uncertainties. We here report the first ever physical characterization of spacetime fuzziness derived constructively within a quantum picture of spacetime, the one provided by spacetime noncommutativity. Our results confirm earlier heuristic arguments suggesting that spacetime fuzziness, while irrelevantly small on terrestrial scales, could be observably large for propagation of particles over cosmological distances. However, we find no Planck-scale-induced lower bound on the uncertainty of the energy of particles, and we observe that this changes how we should picture a quantum spacetime and also imposes a reanalysis of the associated phenomenology.

References in corpus (20)

• Quantum Field Theory on Noncommutative Spaces
• Bicrossproduct structure of $\kappa$-Poincare group and non-commutative geometry
• Loop Quantum Gravity
• Quantum Gravity: a Progress Report
• Classical and Quantum Mechanics of Free \k Relativistic Systems
• An interferometric gravitational wave detector as a quantum-gravity apparatus
• Constraining the energy-momentum dispersion relation with Planck-scale sensitivity using cold atoms
• Relational time in generally covariant quantum systems: four models
• Probing spacetime foam with extragalactic sources
• Spacetime states and covariant quantum theory
• Quantum theory's last challenge
• The phase coherence of light from extragalactic sources - direct evidence against first order Planck scale fluctuations in time and space
• Probing Planck-scale Physics with Extragalactic Sources?
• Scalar field theory on kappa-Minkowski spacetime and translation and Lorentz invariance
• Lack of observational evidence for quantum structure of space-time at Plank scales
• Trajectories for the Wave Function of the Universe from a Simple Detector Model
• No quantum gravity signature from the farthest quasars
• Are High-Redshift Quasars Blurry?
• Using Observations of Distant Quasars to Constrain Quantum Gravity
• Light incoherence due to quantum-gravitational fluctuations of the background space

Cited by in corpus (4)

• Interplay between spacetime curvature, speed of light and quantum deformations of relativistic symmetries
• Misleading inferences from discretization of empty spacetime: Snyder-noncommutativity case study
• Thermal and spectral dimension of (generalized) Snyder noncommutative spacetimes
• Noncommutative spacetime symmetries from covariant quantum mechanics