The High-Temperature Two-Loop Effective Potential of the Electroweak Theory in a General 't Hooft Background Gauge

We calculate the high-temperature two-loop effective potential using a general 't~Hooft background gauge. The dependence on the gauge-fixing parameter $\xi$ is investigated. The effective coupling constant at the critical temperature $g_3(T_c)^2$ is decreased considerably compared to the one-loop result, independent of $\xi$.