author={Jonathan Granot and Arieh Konigl},
  journal={The Astrophysical Journal},
Linear polarization at the level of ~1%-3% has by now been measured in several gamma-ray burst afterglows. Whereas the degree of polarization, P, was found to vary in some sources, the position angle, θp, was roughly constant in all cases. Until now, the polarization has been commonly attributed to synchrotron radiation from a jet with a tangled magnetic field that is viewed somewhat off-axis. However, this model predicts either a peak in P or a 90° change in θp around the "jet break" time in… 

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