Charged boson stars and black holes

Abstract

We consider boson stars and black holes in scalar electrodynamics with a V-shaped scalar potential. The boson stars come in two types, having either ball-like or shell-like charge density. We analyze the properties of these solutions and determine their domains of existence. When mass and charge become equal, the space-times develop a throat. The shell-like solutions need not be globally regular, but may possess a horizon. The space-times then consist of a Schwarzschild-type black hole in the interior, surrounded by a shell of charged matter, and thus a Reissner-Nordström-type space-time in the exterior. These solutions violate black hole uniqueness. The mass of the black hole solutions is related to the mass of the regular shell-like solutions by a mass formula of the type first obtained within the isolated horizon framework.

Construction and physical properties of Kerr black holes with scalar hair

“…These results have been extended recently [63], in particular by constructing higher winding number solutions. For completeness, let us mention that spinning BSs with a self-interacting potential of the Q-ball type (see the discussion of Section 7) have been studied in [64,65], where odd-parity solutions were also first addressed.…”

Gauss–Bonnet boson stars

“…Hence, there are different possibilities to define the "radius" of our boson star solutions. Let us remark that models with a V-shaped potential have been considered [30,31] that possess compact boson stars with a well-defined outer radius (very similar to those of "standard stars") [32][33][34]. Here we follow [35] and define the radius of the boson star as an averaged radial coordinate…”

Compact boson stars in K field theories

“…Compact Q balls (without gravity) for a complex scalar theory with a standard kinetic term but with a V-shaped potential have recently been found in [18] and in [19] (the second paper included also an electromagnetic interaction of the complex scalar, and allows both for ball-shaped and shell-shaped solutions). The gravitational counterpart of the model studied in [19] was investigated in [32], mainly using numerical methods, and the existence of non-singular solutions (both of the ball type and of the shell type) was established. Therefore, the existence of regular self-gravitating compact solutions seems to be a more generic feature for Q balls, analogously to the case of standard (non-compact) Q balls.…”

“…As this thick brane is of the domain wall type, the resulting system is essentially a one-dimensional problem. The coupling of the 3+1 dimensional compact Q balls of the V-shaped class of models of [19] to gravity has been studied recently in [32] mainly using numerical methods.…”