Novel structures and collapse of solitons in nonminimally gravitating dark matter halos

TL;DR

This paper explores how nonminimal gravitational effects influence the formation, structure, and collapse of dark matter solitons, revealing new collapse mechanisms and potential impacts on cosmic structure formation.

Contribution

It introduces the role of gradient-dependent self-interactions and additional gravitational sources in dark matter soliton dynamics, a novel aspect in dark matter modeling.

Findings

Dark matter solitons can collapse due to negative potential curvature regions.

Strong nonminimal effects lead to growth of density perturbations on multiple scales.

Simulations show initial evolution similar to minimal gravitational models.

Abstract

Ultralight dark matter simulations predict condensates with short-range correlation, known as solitons or boson stars, at the centers of dark matter halos. This paper investigates the formation and collapse of dark matter solitons influenced by nonminimal gravitational effects, characterized by gradient-dependent self-interactions of dark matter and an additional source in Poisson's equation for gravity. Our simulations suggest that the initial evolution of dark matter resembles that without nonminimal gravitational effects. However, regions with negative potential curvature may develop, and solitons will collapse when their densities reach certain critical values for both positive and negative coupling constants. With strong nonminimal gravitational effects, we verify that linear density perturbations could grow on both large and small scales, potentially enhancing structure formation.