Relativistic Battery for Magnetogenesis of Collisionless Plasma

Magnetogenesis is a process in which magnetic fields are spontaneously generated and amplified, and

this is often studied as a crossover between cosmology, plasma physics, and astrophysics. It is generally

believed that the magnetic fields initially come from the amplification of a “seed field” by dynamo action.

However, the mechanisms responsible for generating the seed fields remain poorly understood and are an active area of research.

Recently, we adopted the canonical vorticity framework to investigate the magnetogenesis processes and demonstrated

that a pressure-tensor effect named “canonical battery” unifies well-known seed field generation processes and their characteristics [1].

In this talk, we will present a new mechanism called the “relativistic battery effect”, which is in addition to the canonical battery effect and is responsible for new seed field generation

in relativistic plasmas. Analyzing the first moment of the relativistic Vlasov equation reveals that this effect arises due to the non-commutative relationship between the fluid momentum and fluid velocity in relativistic regimes. This effect has been recently verified through particle-in-cell simulations of a shearing plasma. Implications of this effect in other contexts will be discussed.

References;-

1) Laishram, M., Yun, G., Yoon, Y.D. Magnetogenesis via the canonical battery effect. Physical Review Research 6 (2024) https://doi.org/10.1103/PhysRevResearch.6.L032052.