LHAASO Observations Set New Limits on Lorentz Invariance Violation

The Large High Altitude Air Shower Observatory (LHAASO) has reported significant findings related to the gamma-ray burst (GRB) 221009A, which is noted as the brightest gamma-ray burst recorded to date. This observation included the detection of the very early TeV afterglow, marking a milestone in photon statistics within the TeV band from a gamma-ray burst. The LHAASO collaboration utilized this unique observation to impose stringent constraints on the energy dependence of the speed of light in a vacuum, which is associated with Lorentz invariance violation (LIV).

The study indicates that the lower limits on quantum gravity (QG) energy scales are substantial. Specifically, the results show that at a 95% confidence level, the lower limit for linear LIV effects is greater than 10 times the Planck energy, while for quadratic LIV effects, it exceeds 6 × 10^-8 times the Planck energy. These findings improve upon previous best bounds by factors ranging from 5 to 7, suggesting a significant advancement in the understanding of LIV and its implications for quantum gravity theories.

These results are crucial as they provide deeper insights into the fundamental principles of physics, particularly in the context of quantum gravity theories, which attempt to unify general relativity and quantum mechanics. The implications of such findings could influence future research directions in high-energy astrophysics and theoretical physics.