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Figure 1:
Demonstration of the solitonic nature of the (mini-)boson star. Shown are snapshots of the magnitude squared of the complex scalar field for a head-on collision of two identical mini-boson stars. The interacting stars display an interference pattern as they pass through each other, recovering their individual identities after the collision. However, note that the BSs have a larger amplitude after their interaction and so are not true solitons. The collision can therefore be considered inelastic. Reprinted with permission from [49]. See also [141] (e.g., Figure 5.12). |
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Figure 2:
Profiles characterizing static, spherically symmetric boson stars with a few different values of the central scalar field (top left). Reprinted with permission from [141]. |
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Figure 3:
Left: The mass of the boson star as a function of the central value of the scalar field in adimensional units ![]() ![]() ![]() ![]() |
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Figure 4:
The compactness of a stable boson star (black solid line) as a function of the adimensional self-interaction parameter ![]() ![]() |
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Figure 5:
The mass (solid) and the number of particles (dashed) versus central scalar value for charged boson stars with four values of ![]() |
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Figure 6:
Top: Total mass (in units of ![]() ![]() ![]() ![]() |
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Figure 7:
The scalar field in cylindrical coordinates ![]() ![]() ![]() |
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Figure 8:
Left: The maximum of the central value of each of the two scalar fields constituting the multi-state BS for the fraction ![]() ![]() ![]() |
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Figure 9:
Oscillation frequencies of various boson stars are plotted against their mass. Also shown are the oscillation frequencies of unstable BSs obtained from the fully nonlinear evolution of the dynamical system. Unstable BSs are observed maintaining a constant frequency as they approach a stable star configuration. Reprinted with permission from [196]; copyright by APS. |
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Figure 10:
The instability time scale of an excited boson star (the first excitation) to one of three end states: (i) decay to the ground state, (ii) collapse to a black hole, or (iii) dispersal. Reprinted with permission from [15]; copyright by APS. |
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Figure 11:
Very long evolutions of a perturbed, slightly sub-critical, boson star with differing outer boundaries. The central magnitude of the scalar field is shown. At early times ( ![]() ![]() |
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Figure 12:
The evolution of ![]() ![]() |
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Figure 13:
Collision of identical boson stars with large kinetic energy in the Newtonian limit. The total energy (i.e., the addition of kinetic, gravitational and self-interaction) is positive and the collision displays solitonic behavior. Contrast this with the gravity-dominated collision displayed in Figure 14. Reprinted with permission from [26]; copyright by APS. |
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Figure 14:
Collision of identical boson stars with small kinetic energy in the Newtonian limit. The total energy is dominated by the gravitational energy and is therefore negative. The collision leads to the formation of a single, gravitationally bound object, oscillating with large perturbations. This contrasts with the large kinetic energy case (and therefore positive total energy) displayed in Figure 13. Reprinted with permission from [26]; copyright by APS. |
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Figure 15:
The position of the center of one BS in a head-on binary as a function of time for (i) [B-B] identical BSs, (ii) [B-poB] opposite phase pair, and (iii) [B-aB] a boson–anti-boson pair. A simple argument is made, which qualitatively matches these numerical results, as discussed in Section 4.2. Also shown is the expected trajectory from a simple Newtonian two-body estimate. Reprinted with permission from [174]; copyright by APS. |
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Figure 16:
The position of the center of one BS within an orbiting binary as a function of time for the two cases: (i) [B-B] identical BSs and (ii) [B-poB] opposite phase pair. Notice that the orbits are essentially identical at early times (and large separations), but that they start to deviate from each other on closer approach. This is consistent with the internal structure of each member of the binary being irrelevant at large separations. Reprinted with permission from [173]; copyright by APS. |
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Figure 17:
Evolution of a boson star (solid line) perturbed by a shell of scalar field (dashed line). Shown is the mass density ![]() ![]() ![]() ![]() ![]() ![]() |
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Figure 18:
Evolutions of the head-on collisions of identical boson stars boosted toward each other with initial Lorentz factors ![]() ![]() |
http://www.livingreviews.org/lrr-2012-6 |
Living Rev. Relativity 15, (2012), 6
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