Testing Yukawa-like potentials from f(R)-gravity in elliptical galaxies

TL;DR

This study tests Yukawa-like modifications to gravity in elliptical galaxies using stellar kinematics, finding they can explain galaxy dynamics without dark matter, with parameters differing from those in spiral galaxies.

Contribution

First analysis applying f(R)-gravity Yukawa-like potentials to elliptical galaxy kinematics, demonstrating their viability as an alternative to dark matter in these systems.

Findings

Modified potentials fit galaxy data well

Anisotropy distribution aligns with dark matter models

Yukawa strength correlates with scale length and anisotropy

Abstract

We present the first analysis of extended stellar kinematics of elliptical galaxies where a Yukawa--like correction to the Newtonian gravitational potential derived from f(R)-gravity is considered as an alternative to dark matter. In this framework, we model long-slit data and planetary nebulae data out to 7 Re of three galaxies with either decreasing or flat dispersion profiles. We use the corrected Newtonian potential in a dispersion-kurtosis Jeans analysis to account for the mass-anisotropy degeneracy. We find that these modified potentials are able to fit nicely all three elliptical galaxies and the anisotropy distribution is consistent with that estimated if a dark halo is considered. The parameter which measures the "strength" of the Yukawa-like correction is, on average, smaller than the one found previously in spiral galaxies and correlates both with the scale length of the Yukawa-like term and the orbital anisotropy.