Observational aspects of a class of Dark matter spacetimes

TL;DR

This paper introduces a class of static, spherically symmetric spacetimes that model dark matter halos, aligning with galactic rotation curves and astrometric data, and analyzing their causal structure.

Contribution

It proposes a new spacetime model for dark matter halos that matches observational data and explores its causal properties.

Findings

Spacetimes satisfy flat velocity profiles of galactic objects.

Good agreement with S2 star astrometric data.

Central singularity is null in causal structure.

Abstract

Various astrophysical and cosmological observations today serve as an indirect evidence of the existence of dark matter in the universe. In the present work, we propose a class of spacetimes that show some important characteristics relevant to the spacetime of a dark matter halo. These spacetimes are static and spherically symmetric solutions of the Einstein field equations. The proposed spacetimes satisfy the flat velocity profile of a galactic object far away from the center, they give good agreement to the astrometric data of the S2 star, and these also cast a central shadow. Using the Penrose diagram, we show that the causal nature of the central singularity here is null. This single spacetime model for galactic dark matter may therefore be used to explain some of the properties of galactic dynamics at different length scales.