Thesis title: Probing new physics with exotic compact objects: the role of fermion soliton stars
Many of the biggest puzzles in physics, such as the nature of dark matter and the
behavior of spacetime singularities, stem from the interplay between gravity and
quantum mechanics. Compact objects, like neutron stars and black holes, offer a
unique setting to investigate these questions, as they probe strong gravitational
fields and may be the only possible way to observe dark particles. With the recent
discovery of gravitational waves, we now have an uncharted way to study such
extreme environments, potentially shedding light on those fundamental issues.
This thesis focuses on fermion soliton stars, a class of compact objects that emerge
from a theory in which a nonlinear self-interacting scalar field couples with fermions
via a Yukawa interaction, resulting in an effective fermion mass that depends on the
fluid properties. We elucidate the fundamental features of this model and its links
to the Standard Model and beyond. Moreover, we provide distinctive signatures of
the model in the gravitational wave signal, offering a way to distinguish fermion
soliton stars from other types of compact objects.