Electron acceleration by wave turbulence in a magnetized plasma

Astrophysical shocks are commonly revealed by the non-thermal emission of energetic electrons accelerated in situ 1-3 . Strong shocks are expected to accelerate particles to very high energies 4-6 ; however, they require a source of particles with velocities fast enough to permit multiple shock crossings. While the resulting diffusive shock acceleration 4 process can account for observations, the kinetic physics regulating the continuous injection of non-thermal particles is not well understood. Indeed, this injection problem is particularly acute for electrons, which rely on high-frequency plasma fluctuations to raise them above the thermal pool 7,8 . Here we show, using laboratory laser-produced shock experiments, that, in the presence of a strong magnetic field, significant electron pre-heating is achieved. We demonstrate that the key mechanism in producing these energetic electrons is through the generation of lower-hybrid turbulence via shock-reflected ions. Our experimental results are analogous to many astrophysical systems, including the interaction of a comet with the solar wind 9 , a setting where electron acceleration via lower-hybrid waves is possible

Uncertainty, speculation, subjectivity: the expanding judicial role in sovereign debt workouts

This chapter situates a discussion of the NML decision against Argentina within a wider political economy context to better understand the expanding judicial role in sovereign debt workouts. The observed surge in debt demand, growing debt to Gross Domestic Product ratios in debt states increasingly reliant on refinancing their budgetary deficits and a fragmenting consensus that sustained the informal debt workout process so far indicate that sovereign debt speculators that drive demand are making investment decisions in conditions of uncertainty. This paper delineates the political economy contexts in which these speculators evolved as legal subjects. In modern debt markets, the common law courts have become instrumental in entrenching the subjectivity of the debt speculator. This role is an overlooked factor that explains their expansive influence on sovereign debt workouts