A note on the predictability of flat galactic rotation curves

TL;DR

This paper suggests that assuming the Universe's matter as a perfect fluid within Einstein's equations could have predicted flat galactic rotation curves before their observational discovery.

Contribution

It introduces a theoretical perspective linking perfect fluid assumptions to the early prediction of flat rotation curves in galaxies.

Findings

Flat rotation curves can be derived from Einstein's equations with perfect fluid matter

Dark matter hypothesis aligns with predictions from exact solutions of Einstein's field equations

The approach offers a potential alternative explanation for galactic dynamics

Abstract

Based on an exact solution of the Einstein field equations, it is proposed in this note that the dark-matter hypothesis could have led to the prediction of flat galactic rotation curves long before the discovery thereof by assuming that on large scales the matter in the Universe, including dark matter, is a perfect fluid.