Boson stars through the prism of numerical relativity
The existence of fermionic compact objects, such as neutron stars, is supported by a plethora of observational evidence — an intriguing idea is whether one can construct stars made up of the bosonic counterparts. Such theoretical objects are called boson stars, proposed to make up a fraction of the dark matter in our Universe and claimed to be promising horizonless black hole mimickers. In this talk I will discuss the state-of-the-art of numerical evolutions of boson star models in spherical symmetry. In particular, I will discuss how improper initial data construction can lead to spurious physical effects in the evolution of boson star mergers and introduce methods, necessary to remedy such spurious features. I will present our results on boson star head-on collisions of various mass ratios, highlighting the differences from the black hole mergers. Lastly, I will discuss our recent results on the high-precision numerical relativity simulations of quasi-circular boson star inspirals in pursuit of understanding the implications of boson star signatures on the LIGO-Virgo-KAGRA observations.
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