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arXiv · 2210.01833

Two boson stars in equilibrium

P. Cunha·C. Herdeiro·E. Radu·Ya. Shnir
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Abstract

We construct and explore the solution space of two non-spinning, mini-boson stars in equilibrium, in fully non-linear General Relativity (GR), minimally coupled to a free, massive, complex scalar field. The equilibrium is due to the balance between the (long range) gravitational attraction and the (short-range) scalar mediated repulsion, the latter enabled by a $\pi$ relative phase. Gravity is \textit{mandatory}; it is shown no similar solutions exist in flat spacetime, replacing gravity by non-linear scalar interactions. We study the variation of the proper distance between the stars with their mass (or oscillation frequency), showing it can be qualitatively captured by a simple analytic model that features the two competing interactions. Finally, we discuss some physical properties of the solutions, including their gravitational lensing.

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P. Cunha, C. Herdeiro, E. Radu, Ya. Shnir. 2022-10-04. Two boson stars in equilibrium. https://doi.org/10.1103/physrevd.106.124039

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