On dark stars, Planck cores and the nature of dark matter

TL;DR

This paper proposes models of dark stars with Planck cores that could explain dark matter phenomena, galaxy rotation curves, and fast radio bursts through quantum gravity effects and high redshift emissions.

Contribution

It introduces new models of dark stars with Planck cores, linking quantum gravity to observable astrophysical phenomena and dark matter behavior.

Findings

Dark stars can produce flat galaxy rotation curves.

Emission from dark stars can explain fast radio bursts.

Dark matter distribution may vary from hot to cold over cosmological scales.

Abstract

Dark stars are compact massive objects, described by Einstein gravitational field equations with matter. The type we consider possesses no event horizon, instead, there is a deep gravitational well with a very strong redshift factor. Observationally, dark stars can be identified with black holes. Inside dark stars, Planck density of matter is reached, Planck cores are formed, where the equations are modified by quantum gravity. In the paper, several models of dark stars with Planck cores are considered, resulting in the following hypothesis on the composition of dark matter. The galaxies are flooded with low-energetic radiation from the dark stars. The particle type can be photons and gravitons from the Standard Model, can also be a new type of massless particles. The model estimations show that the extremely large redshift factor $z\sim10^{49}$ and the emission wavelength $\lambda_0\sim10^{14}$m can be reached. The particles are not registered directly in the existing dark matter experiments. They come in a density sufficient to explain the observable rotation curves. The emission has a geometric dependence of density on radius $\rho\sim r^{-2}$, producing flat rotation curves. The distribution of sources also describes the deviations from the flat shape. The model provides a good fit of experimental rotation curves. Outbreaks caused by a fall of an external object on a dark star lead to emission wavelength shifted towards smaller values. The model estimations give the outbreak wavelength $\lambda\sim1$m compatible with fast radio bursts. The paper raises several principal questions. White holes with Planck core appear to be stable. Galactic rotation curves in the considered setup do not depend on the matter type. Inside the galaxy, dark matter can be of hot radial type. At cosmological distances, it can behave like the cold uniform type.