Orbital Dynamics of Binary Boson Star Systems

We extend our previous studies of head-on collisions of boson stars by considering orbiting binary boson stars. We concentrate on equal mass binaries and study the dynamical behavior of boson/boson and boson/antiboson pairs. We examine the gravitational wave output of these binaries and compare with other compact binaries. Such a comparison lets us probe the apparent simplicity observed in gravitational waves produced by black hole binary systems. In our system of interest however, there is an additional internal freedom which plays a significant role in the system's dynamics, namely the phase of each star. Our evolutions show rather simple behavior at early times, but large differences occur at late times for the various initial configurations.Comment: 10 pages, 14 figure

Scalar Collapse in AdS

Recently, studies of the gravitational collapse of a scalar field within spherically symmetric AdS spacetimes was presented in \cite{Bizon:2011gg,Jalmuzna:2011qw} which showed an instability of pure AdS to black hole formation. In particular, the work showed that arbitrarily small initial configurations of scalar field evolved through some number of reflections off the AdS boundary until a black hole forms. We consider this same system, extended to include a complex scalar field, and reproduce this phenomena. We present tests of our numerical code that demonstrate convergence and consistency. We study the properties of the evolution as the scalar pulse becomes more compact examining the asymptotic behavior of the scalar field, an observable in the corresponding boundary CFT. We demonstrate that such BH formation occurs even when one places a reflecting boundary at finite radius indicating that the sharpening is a property of gravity in a bounded domain, not of AdS itself. We examine how the initial energy is transferred to higher frequencies --which leads to black hole formation-- and uncover interesting features of this transfer.Comment: 34 pages, 11 figures; Revised to be more consistent with published version: updated references, an added paragraph, and a subsection remove