Improved Bounds on Lorentz Symmetry Violation From High-Energy Astrophysical Sources

Observations of the synchrotron and inverse Compton emissions from ultrarelativistic electrons in astrophysical sources can reveal a great deal about the energy-momentum relations of those electrons. They can thus be used to place bounds on the possibility of Lorentz violation in the electron sector. Recent $\gamma$-ray telescope data allow the Lorentz-violating electron $c^{\nu \mu }$ parameters to be constrained extremely well, so that all bounds are at the level of $7\times {10}^{-16}$ or better.