Seminarium "Teoria cząstek elementarnych i kosmologia"

The appearance of scalar fields with small masses is ubiquitous in physics beyond the Standard Model. In this talk I will describe how such light scalars can play important roles in cosmology, particularly in connection to the origin of the baryons, dark matter, and dark energy of our universe. With regard to the baryons, I will show that a light scalar, such as the QCD axion, can naturally induce baryogenesis. For dark matter, I will present cosmological constraints on scalar dark matter obtained from analyses of the Lyman-alpha forest and the cosmic microwave background. I will also present a novel scenario where dark energy emerges from scalar dark matter.