Detectability of Planck-Scale-Induced Blurring with Gamma-Ray Bursts

TL;DR

This paper explores how quantum spacetime fluctuations at the Planck scale could cause observable blurring in distant astrophysical sources like gamma-ray bursts, and discusses methods to detect such effects.

Contribution

It proposes a high-energy observational approach to detect Planck-scale-induced blurring, consistent with existing HST optical data and Fermi gamma-ray observations.

Findings

Consistent with HST quasar observations showing minimal blurring.

Analysis of Fermi GRB data supports the potential detectability of Planck-scale effects.

Identifies a threshold angular accuracy limit for source localization due to quantum spacetime effects.

Abstract

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.