Self-consistent solution to the semiclassical Einstein equations of a star

TL;DR

This paper provides a non-perturbative, self-consistent interior solution for a static, spherically symmetric star influenced by quantum field theory, revealing ultra-compact configurations without singularities or light rings.

Contribution

It introduces a fully non-perturbative, parameter-free solution to the semiclassical Einstein equations for a star, including ultra-compact states near the Schwarzschild limit.

Findings

Existence of ultra-compact star configurations without singularities.

Stars can be arbitrarily close to the Schwarzschild black hole limit.

Classical astrophysical paradigms are challenged by quantum effects.

Abstract

We present the interior solution for a static, spherically symmetric perfect fluid star backreacted by QFT in four dimensions invoking no arbitrary parameters. It corresponds to a constant energy density star and is fully non-perturbative. The space of solutions includes ultra-compact configurations that have neither singularities nor light rings inside the star and can exist arbitrarily close to the Schwarzschild limit, showing that the classical paradigm of astrophysics does not hold once QFT in curved space is taken into account.