Cosmon Lumps and Horizonless Black Holes

TL;DR

This paper explores horizonless, regular solutions resembling black holes in a scalar field-gravity system, but finds these solutions are dynamically unstable, raising questions about their potential stability.

Contribution

The study introduces a new class of horizonless solutions called cosmon lumps in scalar-tensor gravity, analyzing their properties and stability.

Findings

Solutions closely resemble Schwarzschild black holes externally

Cosmon lumps lack horizons and singularities

Static solutions are dynamically unstable

Abstract

We investigate non-linear, spherically symmetric solutions to the coupled system of a quintessence field and Einstein gravity. In the presence of a scalar potential, we find regular solutions that to an outside observer very closely resemble Schwarzschild black holes. However, these cosmon lumps have neither a horizon nor a central singularity. A stability analysis reveals that our static solutions are dynamically unstable. It remains an open question whether analogous stable solutions exist.