Incompressible fluid inside an astrophysical black hole?

TL;DR

The paper proposes that fermions inside a black hole could form a non-compressible fluid exhibiting quantum Hall effect features, impacting black hole entropy and coupling with Einstein equations, with implications for cosmology and higher dimensions.

Contribution

It introduces a novel model where fermions inside black holes form a non-compressible fluid with quantum Hall properties, linking condensed matter phenomena to black hole physics.

Findings

Fermions inside black holes may form a non-compressible fluid.

Quantum Hall effect features relate to black hole entropy.

Connections to cosmology and higher-dimensional quantum Hall effects are suggested.

Abstract

It is argued that under natural hypothesis the Fermions inside a black hole formed after the collapse of a neutron star could form a non compressible fluid (well before reaching the Planck scale) leading to some features of integer Quantum Hall Effect. The relations with black hole entropy are analyzed. Insights coming from Quantum Hall Effect are used to analyze the coupling with Einstein equations. Connections with some cosmological scenarios and with higher dimensional Quantum Hall Effect are shortly pointed out.