Vortex Structures in a Rotating BEC Dark Matter Component

TL;DR

This paper investigates how a rotating superfluid dark matter condensate with vortex structures can influence galactic rotation curves, suggesting observable effects and guiding future experimental and simulation efforts.

Contribution

It demonstrates the potential impact of vortex lattices in superfluid dark matter on galactic dynamics and explores parameter tuning for matching observations.

Findings

Vortex lattices can cause oscillations in galactic rotation curves.

Fine-tuning boson mass and interaction strength can produce structures resembling spiral galaxy features.

Future experiments and simulations could test these dark matter models.

Abstract

We study the effects of a dark matter component that consists of bosonic particles with ultralight masses in the condensed state. We compare previous studies for both non-interacting condensates and with repulsive two-body terms and show consistency between the proposals. Furthermore, we explore the effects of rotation on a superfluid dark matter condensate, assuming that a vortex lattice forms as seen in ultracold atomic gas experiments. The influence of such a lattice in virialization of gravitationally bound structures and on galactic rotation velocity curves is explored. With fine-tuning of the bosonic particle mass and the two-body repulsive interaction strength, we find that one can have sub-structure on rotation curves that resembles some observations in spiral galaxies. This occurs when the dark matter halo has an array of hollow cylinders. This can cause oscillatory behavior in the galactic rotation curves in similar fashion to the well-known effect of the spiral arms. We also consider how future experiments and numerical simulations with ultracold atomic gases could tell us more about such exotic dark matter proposals.