Limits on Lorentz Violation from Synchrotron and Inverse Compton Sources

We derive new bounds on Lorentz violations in the electron sector from existing data on high-energy astrophysical sources. Synchrotron and inverse Compton data give precisely complementary constraints. The best bound on a specific combination of electron Lorentz-violating coefficients is at the 6×10^-20 level, and independent bounds are available for all the Lorentz-violating c coefficients at the 2×10^-14 level or better. This represents an improvement in some bounds by 14 orders of magnitude.