The continuum spectrum of nonrelativistic multi-frequency Proca stars

TL;DR

This paper systematically studies the continuum spectrum of multi-frequency Proca stars, revealing their interpolation between stationary states and identifying stable configurations, with implications for ultralight dark matter models.

Contribution

It provides the first detailed analysis of the continuum spectrum and stability of multi-frequency Proca stars, expanding understanding of their properties and potential physical relevance.

Findings

Multi-frequency Proca stars interpolate between stationary states.

A subset of these configurations are linearly stable.

Implications for ultralight dark matter particle spin.

Abstract

Multi-frequency Proca stars are excited equilibrium configurations of a selfgravitating massive vector field that coexist with conventional stationary states in the solution space of the $s=1$ Schr\"odinger-Poisson system. In this paper, we present a systematic study of the continuum spectrum of spherical multi-frequency Proca stars and show that they interpolate between the discrete set of stationary states of constant polarization. Furthermore, we also analyze their stability and demonstrate that a subset of these multi-frequency configurations are linearly stable against general perturbations. We briefly discuss the potential implications of multi-frequency states for proving the particle spin in ultralight dark matter models.