Kinetic origin and validity of localized resistivity in resistive MHD models of Petschek reconnection

Ascertain whether the assumption that localized resistivity used to realize Petschek reconnection within resistive magnetohydrodynamic models can be justified as arising from kinetic effects.

Background

Localized resistivity is commonly introduced in resistive MHD simulations to obtain Petschek-type solutions, whereas uniform resistivity typically fails to produce them. This localization is often motivated by hypothesized microphysical processes.

The paper notes that, despite this common assumption, it is unclear whether kinetic physics can indeed produce the effective localized resistivity required by MHD models, highlighting a fundamental multiscale consistency question between kinetic and MHD descriptions.

References

Although the local resistivity is believed to arise from some kinetic effects, whether this assumption is valid remains unclear.

— Multi-hierarchy simulation of Riemann problem for reconnection exhausts  (2603.29638 - Akutagawa et al., 31 Mar 2026) in Section 1, Introduction