Evolution of self-gravitating fluid spheres involving ghost stars

TL;DR

This paper presents exact solutions for the evolution of fluid spheres related to ghost stars, including scenarios where the total mass vanishes, with implications for understanding complex gravitational systems.

Contribution

It introduces new exact solutions describing ghost star evolution and their properties, including conformal symmetries and energy absorption processes.

Findings

Solutions describe adiabatic ghost star evolution with CKV symmetry.

Evolving fluid spheres can absorb energy, reaching zero mass.

All solutions assume vanishing complexity factor.

Abstract

Exact solutions are presented which describe, either the evolution of fluid distributions corresponding to a ghost star (vanishing total mass), or describing the evolution of fluid distributions which attain the ghost star status at some point of their lives. The first two solutions correspond to the former case, they admit a conformal Killing vector (CKV) and describe the adiabatic evolution of a ghost star. Other two solutions corresponding to the latter case are found, which describe evolving fluid spheres absorbing energy from the outside, leading to a vanishing total mass at some point of their evolution. In this case the fluid is assumed to be expansion-free. In all four solutions the condition of vanishing complexity factor was imposed. The physical implications of the results, are discussed