Gauss-Bonnet boson stars

We construct boson stars in (4 + 1)-dimensional Gauss-Bonnet gravity. We study the properties of the solutions in dependence on the coupling constants and investigate in detail their properties. While the thick wall limit is independent of the value of the Gauss-Bonnet coupling, we find that the spiraling behaviour characteristic for boson stars in standard Einstein gravity disappears for large enough values of the Gauss-Bonnet coupling. Our results show that in this case the scalar field can not have arbitrarily high values of the scalar field at the center of the boson star and that it is hence impossible to reach the thin wall limit. Moreover, for large enough Gauss-Bonnet coupling we find a unique relation between the mass and the radius (qualitatively similar to those of neutron stars) which is not present in the Einstein gravity limit. (C) 2013 Elsevier B.V. All rights reserved.