LMP Seminar: Boson stars with nonlinear sigma models

In this talk, I will take you on a cosmic journey, exploring the findings from my master's thesis conducted at KU Leuven in Belgium. The first detection of gravitational waves in 2015 triggered the search for exotic compact objects in the universe. Boson stars, which arise from the coupling of a massive complex scalar field to gravity, have emerged as a promising candidate. A variety of scalar potentials, giving rise to different types of boson stars, have been studied in the literature. Surprisingly, the effect of promoting the kinetic term of the scalar field to a nonlinear sigma model - an extension that is naturally motivated by UV completions of gravity like string theory - has never been studied before. I will discuss the implications of this novel extension on the properties of the obtained boson stars.