Weibel's theorem

Weibel's theorem addresses how the behavior of charged particles, like electrons, in a plasma changes when a magnetic field is applied. It states that if a plasma has uneven energy distribution among its particles—meaning some particles move faster than others—then introducing a magnetic field can cause these differences to grow exponentially, leading to turbulence and magnetic field amplification. Essentially, the theorem explains how certain initial imbalances in a plasma's particle energies can trigger the rapid development of magnetic structures, which is important for understanding magnetic fields in astrophysical phenomena and plasma physics.