Possible influence of a cosmic repulsion on large-scale jets: geometric viewpoint

TL;DR

This paper explores how cosmic repulsion influences large-scale jet formations around massive objects, suggesting that it causes matter to cluster near a static radius before expanding outward, which may relate to observed radio lobes.

Contribution

It introduces a geometric analysis of radial geodesics in Schwarzschild-de Sitter spacetime, linking cosmic repulsion to large-scale jet phenomena around massive galaxies.

Findings

Particles tend to cluster near the static radius due to cosmic repulsion.

Clustering occurs at tens to hundreds of kiloparsecs from the center.

This clustering may explain the formation of large radio lobes.

Abstract

Cosmic repulsion represented by a small positive value of the cosmological constant changes significantly properties of central gravitational fields at large distances, leading to existence of a static (or turnaround) radius where gravitational attraction of a center is just balanced by cosmic repulsion. Analyzing behavior of radial timelike geodesics in the Schwarzschild-de Sitter spacetime near its static radius we show that the particles with specific energy close to unity have tendency to slow down and cluster just below the static radius, forming clumps which, subsequently, start to expand uniformly due to cosmic repulsion. For central masses of $(10^6$-$10^{11}){\rm M_{\odot}}$ and current value of the cosmological constant $1.1\times 10^{-52}\,{\rm m^{-2}}$, this phenomenon takes place at distances of tens to hundreds of kiloparsecs from the center, being comparable with distances in which huge radio-lobes from some active galaxies were observed.