ℓ-boson stars

Abstract

We present new, fully nonlinear numerical solutions to the static, spherically symmetric Einstein-Klein-Gordon system for a collection of an arbitrary odd number N of complex scalar fields with an internal symmetry and no self-interactions. These solutions, which we dub -boson stars, are parametrized by an angular momentum number ℓ =(N - 1)/2, an excitation number n, and a continuous parameter representing the amplitude of the fields. They are regular at every point and possess a finite total mass. For ℓ = 0the standard spherically symmetric boson stars are recovered. We determine their generalizations for ℓ ≤ 0, and show that they give rise to a large class of new static configurations which might have a much larger compactness ratio than stars.