An exact static two-mass solution using Nariai spacetime

TL;DR

This paper demonstrates the existence of static, spherically symmetric two-mass solutions with incompressible matter, using Nariai spacetime, where the stars are held apart by a positive cosmological constant without a cosmological horizon.

Contribution

It introduces a novel exact solution describing two stars in equilibrium within Nariai spacetime, including charged cases, expanding understanding of static multi-mass configurations.

Findings

Existence of static two-star solutions in Nariai spacetime.

Stars can be oppositely charged and still remain static.

Negative pressure from the cosmological constant balances gravitational attraction.

Abstract

We show the existence of static, spherically symmetric spacetimes containing two stars of incompressible matter, possibly oppositely charged. The stars are held apart by the negative pressure of a positive cosmological constant but there is no cosmological horizon separating them. The spacetime between the stars is given by the Nariai solution, or a slight generalisation thereof in the charged case.