INVERSE TRANSFER IN RECONNECTING PLASMAS

Liu, Zhou & Loureiro (ApJ Letters, Dec 2025)
WORMS
STRUCTURES: 0
G = -0.367
WORM REGIME (G < 0): The firehose instability nullifies magnetic tension, preventing structures from merging. Flux ropes elongate into "worms" that drift and fragment. Energy cascades to smaller scales (direct cascade).
THE KEY INSIGHT

In high-β plasmas, the firehose instability can suppress magnetic tension, preventing the usual inverse cascade. Only when the guide field is strong enough (G > 0) does coalescence occur, allowing small-scale magnetic structures to merge into larger ones.

PHASE SPACE (Δ vs β∥)

Op Point: Δ=-0.50, β∥=10.0
Firehose Threshold: -0.200
FIREHOSE ACTIVE
G-CRITERIONG = -0.367
Guide Field (B̂_G)1.00
Beta Parallel (β∥)10.0
Anisotropy (Δ)-0.50