# Gravitational electromotive force in magnetic reconnection around Schwarzschild black holes

## TL;DR

This paper analytically investigates how gravitational electromotive forces influence magnetic reconnection near Schwarzschild black holes, revealing that gravity can enhance reconnection rates through two-fluid effects and effective resistivity.

## Contribution

It introduces a generalized relativistic MHD model incorporating two-fluid effects to analyze gravitational impacts on magnetic reconnection around black holes.

## Key findings

- Gravitational electromotive force couples with two-fluid effects to drive reconnection.
- Departure from quasi-neutrality in curved spacetime creates effective resistivity.
- Gravity enhances the magnetic reconnection rate near Schwarzschild black holes.

## Abstract

We analytically explore the effects of the gravitational electromotive force on magnetic reconnection around Schwarzschild black holes through a generalized general-relativistic magnetohydrodynamic model that retains two-fluid effects. It is shown that the gravitational electromotive force can couple to collisionless two-fluid effects and drive magnetic reconnection. This is allowed by the departure from quasi-neutrality in curved spacetime, which is explicitly manifested as the emergence of an effective resistivity in Ohm's law. The departure from quasi-neutrality is owed to different gravitational pulls experienced by separate parts of the current layer. This produces an enhancement of the reconnecion rate due to purely gravitational effects.