On the Space Time of a Galaxy

TL;DR

This paper presents an exact spherical solution to Einstein's equations with scalar fields and dust, modeling a galaxy's core and halo, and analyzing its rotation curves.

Contribution

It introduces a novel exact solution combining scalar fields and dust to model galactic structures and rotation curves.

Findings

The solution models a galactic core with an oscillaton and a surrounding scalar field halo.

Rotation curves derived from the model match observed galactic rotation profiles.

The model provides a unified description of supermassive objects and dark matter halos.

Abstract

We present an exact solution of the averaged Einstein's field equations in the presence of two real scalar fields and a component of dust with spherical symmetry. We suggest that the space-time found provides the characteristics required by a galactic model that could explain the supermassive central object and the dark matter halo at once, since one of the fields constitutes a central oscillaton surrounded by the dust and the other scalar field distributes far from the coordinate center and can be interpreted as a halo. We show the behavior of the rotation curves all along the background. Thus, the solution could be a first approximation of a ``long exposition photograph'' of a galaxy.