Models of spherical shells as sources of Majumdar-Papapetrou type spacetimes

TL;DR

This paper develops relativistic models of spherical shells within Majumdar-Papapetrou spacetimes, using Newtonian potentials to generate conformastatic solutions, and analyzes their physical properties and orbital stability.

Contribution

It introduces a method to construct relativistic spherical shell models from Newtonian potentials and applies it to specific examples, including a composite system with a disk and halo.

Findings

Models satisfy all energy conditions.

Stable circular orbits are identified.

Relativistic shell models extend Newtonian analogs.

Abstract

By starting with a seed Newtonian potential-density pair we construct relativistic thick spherical shell models for a Majumdar-Papapetrou type conformastatic spacetime. As a simple example, we consider a family of Plummer-Hernquist type relativistic spherical shells. As a second application, these structures are then used to model a system composite by a dust disk and a halo of matter. We study the equatorial circular motion of test particles around such configurations. Also the stability of the orbits is analyzed for radial perturbation using an extension of the Rayleigh criterion. The models considered satisfying all the energy conditions.