Detectability of Planck-Scale-Induced Blurring with Gamma-Ray Bursts
  Microscopic fluctuations inherent to the fuzziness of spacetime at the Planck
scale might accumulate in wavefronts propagating a cosmological distance and
lead to noticeable blurring in an image of a pointlike source. Distant quasars
viewed in the optical and ultraviolet with Hubble Space Telescope (HST} may
show this weakly, and if real suggests a stronger effect should be seen for
Gamma-Ray Bursts (GRBs) in X-rays and gamma-rays. Those telescopes, however,
operate far from their diffraction limits. A description of how
Planck-scale-induced blurring could be sensed at high energy, even with cosmic
rays, while still agreeing with the HST results is discussed. It predicts
dilated apparent source size and inflated uncertainties in positional
centroids, effectively a threshold angular accuracy restricting knowledge of
source location on the sky. These outcomes are found to be consistent with an
analysis of the 10 highest-redshift GRB detections reported for the Fermi
satellite. Confusion with photon cascade and scattering phenomena is also
possible; prospects for a definitive multiwavelength measurement are
considered.
