In 1959 Weibel demonstrated that when a QED plasma has a temperature anisotropy there exist unstable transverse magnetic excitations which grow exponentially fast. In this paper we will review how to determine the growth rates for these unstable modes in the weak-coupling and ultrarelativistic limits in which the collective behavior is describable in terms are so-called “hard-loops”. We will sh...

Plasma is a partially or fully ionized gas. Ionized gas contains free electrons and ions which carry electric charges. Thus, plasma is subject to electromagnetic forces and can react to external electric and magnetic fields. Moreover, since plasma contains free charge carriers, their relative motion can also set internal electric and magnetic fields, which in turn also influence their dynamics....