Novel instabilities in counter-streaming nonabelian fluids

The dynamics of strongly interacting particles are governed by Yang–Mills (Y-M) theory, which is a natural generalization of Maxwell Electrodynamics (ED). Its quantized version is known as quantum chromodynamics (QCD) (Gross and Wilczek, 1973; Politzer, 1973; ’t Hooft, 1972[1], [2], [3]) and has been very well studied. Classical Y-M theory is proving to be equally interesting because of the central role it plays in describing the physics of quark-gluon plasma (QGP) — which was prevalent in the early universe and is also produced in relativistic heavy ion collision experiments. This calls for a systematic study of classical Y-M theories. A good insight into classical Y-M dynamics would be best obtained by comparing and contrasting the Y-M results with their ED counterparts. In this article, a beginning has been made by considering streaming instabilities in Y-M fluids. We find that in addition to analogues of ED instabilities, novel nonabelian modes arise, reflecting the inherent nonabelian nature of the interaction. The new modes exhibit propagation/ growth, with growth rates that can be larger than what we find in ED. Interestingly, we also find a mode that propagates without getting affected by the medium.