Strains and axial outflows in the field of a rotating black hole

TL;DR

This paper investigates how curvature and inertial strains influence the formation of jet-like axial outflows in the vicinity of a rotating black hole, emphasizing the kinematic effects without addressing the physical jet formation mechanisms.

Contribution

It reveals the role of Lorentz-invariant properties of the Weyl tensor in shaping axial outflows near Kerr black holes, highlighting a purely kinematic explanation for jet-like structures.

Findings

Curvature and inertial strains can produce jet-like outflows.

Lorentz invariance of the Weyl tensor's electric and magnetic parts influences outflow shape.

Kinematic effects alone can mimic jet formation without physical process modeling.

Abstract

We study the behaviour of an initially spherical bunch of accelerated particles emitted along trajectories parallel to the symmetry axis of a rotating black hole. We find that, under suitable conditions, curvature and inertial strains compete to model the shape of axial outflows of matter contributing to generate jet-like structures. This is of course a purely kinematical effect which does not account by itself for physical processes underlying the formation of jets. In our analysis a crucial role is played by a property of the electric and magnetic part of the Weyl tensor to be Lorentz-invariant boosting along the axis of symmetry in Kerr spacetime.