Simulations of galaxies in an expanding Universe with modified Newtonian dynamics (MOND) and with modified gravitational attractions (MOGA)

Fuente: arXiv
Saved in:
Bibliographic Details
Main Author: Toxvaerd, Søren
Format: Preprint
Published: 2024
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866916218050445312
author Toxvaerd, Søren
author_facet Toxvaerd, Søren
contents The stability of galaxies is either explained by the existence of dark matter or caused by a modification of Newtonian acceleration (MOND). Here we show that the modification of the Newtonian dynamics can equally well be obtained by a modification of Newton's law of universal gravitational attraction (MOGA), by which an inverse square attraction from a distant object is replaced with an inverse attraction. This modification is often proposed in the standard model, and with the modification of the attraction caused by dark matter. The recently derived algorithm, Eur. Phys. J. Plus 137, 99 (2022); Class. Quantum Grav. 39, 225006 (2022), for classical celestial dynamics is used to simulate models of the Milky Way in an expanding universe and with either MOND or MOGA. The simulations show that the galaxies with MOND dynamics are unstable whereas MOGA stabilizes the galaxies. The rotation velocities for objects in galaxies with classical Newtonian dynamics decline inversely proportional to the square root of the distance $r$ to the galaxy's center. However, the rotation velocities are relatively independent of $r$ for MOGA and qualitatively in agreement with experimentally determined rotation curves for galaxies in the Universe. The modification of the attractions may be caused by the masses of the objects in the central part of the galaxy by the lensing of gravitational waves from far-away objects in the galaxy.
format Preprint
id arxiv_https___arxiv_org_abs_2403_02848
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Simulations of galaxies in an expanding Universe with modified Newtonian dynamics (MOND) and with modified gravitational attractions (MOGA)
Toxvaerd, Søren
Astrophysics of Galaxies
The stability of galaxies is either explained by the existence of dark matter or caused by a modification of Newtonian acceleration (MOND). Here we show that the modification of the Newtonian dynamics can equally well be obtained by a modification of Newton's law of universal gravitational attraction (MOGA), by which an inverse square attraction from a distant object is replaced with an inverse attraction. This modification is often proposed in the standard model, and with the modification of the attraction caused by dark matter. The recently derived algorithm, Eur. Phys. J. Plus 137, 99 (2022); Class. Quantum Grav. 39, 225006 (2022), for classical celestial dynamics is used to simulate models of the Milky Way in an expanding universe and with either MOND or MOGA. The simulations show that the galaxies with MOND dynamics are unstable whereas MOGA stabilizes the galaxies. The rotation velocities for objects in galaxies with classical Newtonian dynamics decline inversely proportional to the square root of the distance $r$ to the galaxy's center. However, the rotation velocities are relatively independent of $r$ for MOGA and qualitatively in agreement with experimentally determined rotation curves for galaxies in the Universe. The modification of the attractions may be caused by the masses of the objects in the central part of the galaxy by the lensing of gravitational waves from far-away objects in the galaxy.
title Simulations of galaxies in an expanding Universe with modified Newtonian dynamics (MOND) and with modified gravitational attractions (MOGA)
topic Astrophysics of Galaxies
url https://arxiv.org/abs/2403.02848