Elliptical galaxies kinematics within general relativity with renormalization group effects

TL;DR

This paper explores a modified gravity model based on renormalization group effects in general relativity, successfully explaining elliptical galaxy kinematics without dark matter, and compares it to MOND, highlighting its better fit for observed velocity dispersions.

Contribution

The study extends a renormalization group corrected gravity model to elliptical galaxies, demonstrating its effectiveness in fitting galaxy kinematics without dark matter, unlike MOND.

Findings

RGGR model fits elliptical galaxy velocity dispersions well.

MOND shows significant discrepancies with observed data.

RGGR compatible with lower mass-to-light ratios.

Abstract

The renormalization group framework can be applied to Quantum Field Theory on curved space-time, but there is no proof whether the beta-function of the gravitational coupling indeed goes to zero in the far infrared or not. In a recent paper we have shown that the amount of dark matter inside spiral galaxies may be negligible if a small running of the General Relativity coupling G is present. Here we extend the proposed model to elliptical galaxies and present a detailed analysis on the modeling of NGC 4494 (an ordinary elliptical) and NGC 4374 (a giant elliptical). In order to compare our results to a well known alternative model to the standard dark matter picture, we also evaluate NGC 4374 with MOND. In this galaxy MOND leads to a significative discrepancy with the observed velocity dispersion curve and has a significative tendency towards tangential anisotropy. On the other hand, the approach based on the renormalization group and general relativity (RGGR) could be applied with good results to these elliptical galaxies and is compatible with lower mass-to-light ratios (of about the Kroupa IMF type).