Title: Conditions for Relativistic Magnetic Reconnection under the Presence of Shear Flow and Guide Field

Abstract: The scaling of the relativistic reconnection outflow speed is studied in the presence of both shear flows parallel to the reconnecting magnetic fields and guide fields pointing out of the reconnection plane. In nonrelativistic reconnection, super-Alfv\'enic shear flows have been found to suppress reconnection. We extend the analytical model of this phenomenon to the relativistic regime and find similar behavior, which is confirmed by particle-in-cell simulations. Unlike the nonrelativistic limit, the addition of a guide field lowers the in-plane Alfv\'en velocity, contributing to slower outflow jets and the more efficient suppression of reconnection in strongly magnetized plasmas.