Charged scalar-tensor boson stars: Equilibrium, stability, and evolution -art. no. 104050

Citation
Aw. Whinnett et Df. Torres, Charged scalar-tensor boson stars: Equilibrium, stability, and evolution -art. no. 104050, PHYS REV D, 6010(10), 1999, pp. 4050
Citations number
62
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physics
Journal title
PHYSICAL REVIEW D
ISSN journal
0556-2821 → ACNP
Volume
6010
Issue
10
Year of publication
1999
Database
ISI
SICI code
0556-2821(19991115)6010:10<4050:CSBSES>2.0.ZU;2-Q
Abstract
We study charged boson stars in scalar-tensor (ST) gravitational theories. We analyze the weak field limit of the solutions and analytically show that there is a maximum charge to mass ratio for the bosons above which the wea k held solutions are not stable. This charge limit can be greater than the GR limit for a wide class of ST theories. We numerically investigate strong held solutions in birth the Brans-Dicke and power law ST theories. We find that the charge limit decreases with increasing central boson density. We discuss the gravitational evolution of charged and uncharged boson stars in a cosmological setting and show how, at any point in its evolution, the ph ysical properties of the star may be calculated by a rescaling of a solutio n whose asymptotic value of the scalar field is equal to its initial asympt otic value. We focus on evolution in which the particle number of the star is conserved and we find that the energy and central density of the star de crease as the cosmological time increases. We also analyze the appearance o f the scalarization phenomenon recently discovered for neutron stars config urations and, finally, we give a short discussion on how making the correct choice of mass influences the argument over which conformal frame, the Ein stein frame or the Jordan frame, is physical. [S0556-2821(99)00122-8].