Interior of Schwarzschild in semiclassical gravity

TL;DR

This paper explores how quantum effects modify the internal structure of collapsing stars, preventing infinite pressure and suggesting extremely high densities near the Schwarzschild radius, with implications for black hole formation.

Contribution

It introduces a semiclassical gravity model showing quantum effects bound pressure and alter the core structure of collapsing stars.

Findings

Quantum effects bound pressure in collapsing stars.

A negative energy core appears due to quantum effects.

Density reaches Planck scale near the Schwarzschild radius.

Abstract

In Einstein gravity, matter with an arbitrarily small density can be a black hole. Pressure in the star diverges if size of the star is smaller than 9/8 of the Schwarzschild radius, implying the gravitational collapse into a black hole. By taking quantum effects of matter, however, pressure is bounded from above, and a core with negative energy appears instead. Density of matter increases and eventually reaches the cut-off scale as size of the star approaches the Schwarzschild radius. This result implies that density must be very large as the Planck scale if the star is put inside the Schwarzschild radius.