Boson stars: Rotation, formation, and evolution
The existence of rotating boson stars in general relativity is studied. One considers the Lagrange density of a gravitationally coupled complex scalar field, and the spacetime is supposed to be isotropic, stationary and axisymmetric. It is shown that the total angular momentum of a rotating boson star is proportional to the particle number \(N\). A 3D plot of the energy density \(\rho\) as function of cylindrical coordinates \(\widetilde x= x\sin\theta\) and \(z=x\cos\theta\) \((\theta\) with respect to the equatorial plane) is given. The plot shows that \(\rho\) vanishes at the axis of rotation due to ``centrifugal forces''. There is also a nearby maximum of the energy density that extends to a mass torus. The authors suggest a model of a relativistic accretion disk which is thickened along the equator. Finally, the possibility to detect boson stars by gravitational lensing or gravitational redshift is pointed out, and some results on boson stars within scalar-tensor theories are given.
scientific article; zbMATH DE number 1364638