Fermion Soliton Stars with Asymmetric Vacua

Abstract

Fermion soliton stars are a motivated model of exotic compact objects in which a nonlinear self-interacting real scalar field couples to a fermion via a Yukawa term, giving rise to an effective fermion mass that depends on the fluid properties. Here we continue our investigation of this model within General Relativity by considering a scalar potential with generic asymmetric vacua. This case provides fermion soliton stars with a parametrically different scaling of the maximum mass relative to the model parameters, showing that the special case of symmetric vacua, in which we recover our previous results, requires fine tuning. In the more generic case studied here the mass and radius of a fermion soliton star are comparable to those of a neutron star for natural model parameters at the GeV scale. Finally, the asymmetric scalar potential inside the star can provide either a positive or a negative effective cosmological constant in the interior, being thus reminiscent of gravastars or anti-de Sitter bubbles, respectively. In the latter case we find the existence of multiple, disconnected, branches of solutions.

9 pages, 7 figures. v2: matches version accepted in PRD

References in corpus (3)

• Fermion soliton stars
• On the inexistence of solitons in Einstein-Maxwell-scalar models
• Solitonic Gravastars in a U(1) gauge Higgs model

Cited by in corpus (12)

• The Science of the Einstein Telescope
• Tidal Love numbers and approximate universal relations for fermion soliton stars
• Compact objects in and beyond the Standard Model from non-perturbative vacuum scalarization
• The simplest model of a scalarized black hole in the Einstein-Klein-Gordon theory
• Black Holes from Fermi Ball Collapse
• Cosmology and nuclear-physics implications of a subsolar gravitational-wave event
• Gravitating Scalarons with Inverted Higgs Potential
• Geodesic Motion of Test Particles around the Scalar Hairy Black Holes with Asymmetric Vacua
• Shadow of the Scalar Hairy Black Hole with Inverted Higgs Potential
• Analytical solutions for Maxwell-scalar system on radially symmetric spacetimes
• Tidal Love numbers and the dynamical instability of AdS bubbles
• On a Class of Exact Arbitrarily Differentiable de Sitter Cores with Kerr Exteriors: Possible gravastar or regular black hole mimickers