Multishell Dirac fermions in the Einstein-Dirac system

TL;DR

This paper explores self-localized multifermion configurations in a spherically symmetric Einstein-Dirac system, revealing complex shell structures, interactions, and information-theoretic properties that extend previous models.

Contribution

It introduces a multishell fermion model in Einstein-Dirac systems, considering full shell filling and analyzing shell interactions and entropy correlations.

Findings

Multishell fermion configurations exhibit multipeak and fragmentation structures.

Intershell interactions influence the stability and structure of solutions.

Shannon entropy correlates with structural deformations of the fermion shells.

Abstract

We present multifermions in the spherically symmetric Einstein-Dirac system. Dirac fermions are self-localized within a spherically symmetric Einstein gravity, i.e., the Schwarzschild-like space-time metric. Most of previous studies of the Einstein-Dirac system are restricted to two neutral fermions or to many fermions with the same high-angular momentum filling a single shell. Our model considers full-filling of fermions in multiple shells, similarly to the conventional nuclear shell model. We solve the model for fermion numbers $N_\textrm{f}=2,6,12$ and $20$, which can realize a spherically symmetric system. Even single-shell multifermions exhibit a multipeak structure and fragmentation in the high redshift region. The behavior observed in our multishell model can be explained by interactions between the shells and resulting delocalization. We also investigate the pressure of the solutions which defines the existence (or absence) of intershell interactions. The radial pressure is attractive, supporting compactness of the solutions. Finally, we show the correlations between the nontrivial changes in the Shannon entropy (a logarithmic measure of information content) and the structural deformations of the solutions.