MG11 
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Scalar Field Dark Matter: beyond the spherical symmetry

The emission spectrum from a simple accretion disc model around a compact object is compared for the cases of a black hole (BH) and a boson star (BS) playing the role of the central object. It was found in the past that such spectrum presents a hardening at high frequencies, however, here it is shown that the self-interaction and compactness of the BS have the effect of softening the spectrum, the less compact the star is the softer the emission spectrum at high frequencies. Because the mass of the boson fixes the mass of the star and the self-interaction the compactness of the star we find that for certain values of the BSs parameters it is possible to produce similar spectra to those generated when the central object is a BH. This result presents two important implications: i) using this simple accretion model a BS can supplant a BH in the role of compact object accreting matter and ii) within the assumptions of the present accretion disc model we do not find a prediction that could help at distinguishing a BH from a BS with appropriate parameters of mass and self-interaction.

Nonspherical perturbations of Boson Stars

Using full 3d numerical calculations we perturb a boson star. Within a series of numerical simulations, we explicitly extract the Zerilli and Newman-Penrose scalar $\Psi_4$ gravitational waveforms when the stars are subjected to different types of perturbations. Boson star systems have rapidly decaying nonradial quasinormal modes and thus the complete gravitational waveform could be extracted for all configurations studied. The gravitational waves emitted from stable, critical, and unstable boson star configurations are analyzed and the numerically observed quasinormal mode frequencies are compared with known linear perturbation results. The superposition of the high frequency nonspherical modes on the lower frequency spherical modes was observed in the metric oscillations when perturbations with radial and nonradial components were applied. The collapse of unstable boson stars to black holes was simulated. The apparent horizons were observed to be slightly nonspherical when initially detected and became spherical as the system evolved.

Scalar field dark matter: beyond the spherical collapse

We show the evolution of non-spherically symmetric balls of a self-gravitating scalar field in the Newtonian regime or equivalently an ideal self-gravitating condensed Bose gas. In order to do so, we use a finite differencing approximation of the Shcr\"odinger-Poisson (SP) system of equations with axial symmetry in cylindrical coordinates. Our results indicate: 1) that spherically symmetric equilibrium configurations are stable against non-spherical perturbations and 2) that such equilibrium configurations of the SP system are late-time attractors for non-spherically symmetric initial profiles of the scalar field, which is a generalization of such behavior for spherically symmetric initial profiles. Our system and the boundary conditions used, work as a model of scalar field dark matter collapse after the turnaround point. In such case, we have found that the scalar field overdensities tolerate non-spherical contributions to the profile of the initial fluctuation.