New collective plasma physics in different electromagnetic-field configurations

Identify and characterize additional collective plasma phenomena triggered by radiation-reaction-driven cooling in electromagnetic-field configurations different from the uniform magnetic field considered here, under extreme laboratory or astrophysical conditions.

Background

The paper demonstrates that radiation reaction can drive strong kinetic features (ring distributions, anisotropies) leading to instabilities such as the synchrotron firehose and electron cyclotron maser in a uniform magnetic field. These are presented as examples of collective plasma behavior emerging from non-conservative, anisotropic cooling.

The authors conjecture that these are only the first examples and that exploring other electromagnetic-field configurations may reveal further collective phenomena driven by radiation reaction, motivating systematic investigation beyond the specific field geometry analyzed.