# Evolution of spiral galaxies in nonlocal gravity

## TL;DR

This study uses high-resolution simulations to compare the evolution of disk galaxies under nonlocal gravity versus standard dark matter models, revealing differences in bar formation and dynamics.

## Contribution

It introduces a novel comparison between nonlocal gravity and dark matter models in galaxy evolution through detailed N-body simulations.

## Key findings

- Higher bar instability rate in nonlocal gravity model
- Bars are weaker and faster in nonlocal gravity
- Differences in long-term galaxy dynamics between models

## Abstract

We study the evolution of simulated disk galaxies in the context of a nonlocal theory of gravity. In this theory the appearance of the dark matter problem in cosmology and astrophysics is a manifestation of the nonlocality of the gravitational interaction. Using high-resolution N-body simulations, we investigate the dynamical evolution of disk galaxies and compare the result with the standard dark matter viewpoint. Specifically, we construct two exponential galaxy models, one in nonlocal gravity (NLG) and the other surrounded by a Plummer dark matter halo. Both systems start from the same baryonic matter distribution, particles velocities, random velocities and the initial Toomre's parameter. However, although the initial conditions are the same in both models, their long-term dynamics reveals some notable differences. For example, it turns out that the bar instability happens with higher rate in NLG model compared with the standard case. On the other hand, at the end of the simulation, we find that bars are weaker and faster in NLG compared with the standard case.