Translation of reconnection-mediated cascade to the supersonic regime

Ascertain whether the reconnection-mediated energy cascade identified in subsonic or strong-field MHD turbulence—featuring tearing of current sheets and a steep k^{-11/5} spectrum—occurs in supersonic, compressible MHD turbulence with dynamo-generated fields, or whether shock-driven disruption of current sheets prevents this cascade from manifesting; characterize the impact of supersonic shocks on current-sheet stability and spectral signatures.

Background

In the authors’ highest-resolution supersonic simulations, plasmoid chains are observed within current sheets, particularly in void regions, suggesting the presence of tearing instabilities at scales kL/2π ≳ 100. However, the global spectra do not exhibit the expected steepening attributed to reconnection-mediated dynamics.

The paper highlights that supersonic shocks and strong density gradients may disrupt current-sheet coherence, potentially altering or suppressing reconnection signatures in the supersonic regime. Clarifying whether and how the reconnection-mediated cascade translates to supersonic compressible turbulence is therefore unresolved and critical for interpreting spectral behavior in astrophysical plasmas.