Single Parameter Model for Galaxy Rotation Curves

TL;DR

This paper introduces a simple, one-parameter model that predicts galaxy rotation curves from luminous matter alone, challenging dark matter assumptions and fitting a large galaxy sample effectively.

Contribution

It presents a novel, low-parameter model linking luminous matter to rotation curves, successfully fitting a large galaxy dataset and offering insights into dark matter's role.

Findings

Model fits 175 galaxy rotation curves successfully.

Average reduced chi square compares favorably with dark matter models.

Power law relationship observed between free parameter and galactic properties.

Abstract

One key piece of evidence for dark matter is the rotation-curve problem: the disagreement between measured galactic rotation curves and their luminous mass. A novel solution to this problem is presented here, in a model that predicts observed Doppler-shifted spectra based only on the luminous matter estimates and one free model parameter. This model is applied to fit the rotation curves of the SPARC sample of 175 galaxies, yielding mass-to-light ratios, goodness of fit measurements, and the free parameter. The model's average reduced chi square compares favorably with the dark matter model for the same data, and more galaxies are successfully fit by this model. The model provides a useful formulation linking luminous matter to the observed rotation curves, with the dark matter contribution to galaxies encoded in two transformation terms of the luminous mass. It also offers a lower-parameter characterization of the rotation curve problem, and a power law relationship between the model's free parameter and galactic photometric quantities is observed, potentially removing the need for the free parameter.