Abstract

Boson stars (BSs)— self-gravitating configurations of a complex scalar field— provide a simple, numerically tractable model for a class of exotic compact objects (ECOs). I will discuss two recent works showing how dynamical evolutions of spacetimes involving BSs can be used to address theoretical and observational challenges related to ECOs. First, I will cover how evolutions of a class of ultracompact BSs, which possess a pair of light rings, find no evidence for the efficacy of a conjectured dynamical instability affecting ultraompact objects, thus presenting the first long-term stable evolutions of black hole mimickers and raising the possibility that a population of such objects could exist in the universe. Secondly, I will discuss results from a study of black hole-boson star binary mergers, focusing on prospects for attempts to build gravitational wave template banks for astrophysical ECO searches in a model-agnostic manner.