Magnetic reconnection under centrifugal and gravitational electromotive forces

TL;DR

This paper investigates how centrifugal and gravitational electromotive forces influence magnetic reconnection near Kerr black holes, revealing distinct mechanisms that enhance reconnection rates.

Contribution

It introduces a detailed analysis of the separate effects of gravitational and centrifugal forces on plasma behavior during magnetic reconnection in curved spacetime.

Findings

Both forces increase the reconnection rate.

Gravitational force causes charge separation, breaking plasma quasi-neutrality.

Centrifugal force reduces the effective length of the current sheet.

Abstract

We examine the physical implications of the centrifugal and gravitational electromotive forces on magnetic reconnection in a Kerr black hole background. We find that both forces increase the reconnection rate, though the underlying mechanisms differ substantially. The gravitational force leads to a separation of charge density, breaking the quasi-neutrality of the plasma. In contrast, the centrifugal electromotive force affects the electric current by reducing the effective length of the current sheet. This reduction arises from the non-Euclidean spatial geometry observed by a locally comoving observer with respect to the rotating sheet. This phenomenon amplifies both the transport of charged carriers and the thermal-inertia effect within the current sheet, irrespective of the presence of a black hole.