Ph.D. Thesis: Phenomenological Studies in Cosmoparticle Physics. Expansion Histories in non-Einstein Gravity and Dark Matter at the Large Hadron Collider
by
Sara Rydbeck(DESY)
→
Europe/Stockholm
FA32
FA32
Description
As the Big Bang model has become established, the fields of cosmology and particle physics have
become intertwined. A range of observations forces us to consider the phenomena of dark matter
and dark energy. This interpretation is based on our understanding of gravity, while the standard
model of particle physics describes the other fundamental forces in nature and fails to explain the
dark components. This thesis includes two different types of studies where hypotheses of physics
beyond the standard models of particle physics and cosmology are faced with what observations
and experiments can tell us.
The first one deals with the possibility that our theory of gravity is what has to be modified
at large distances to explain the dark energy, which then need not be a contribution to the energy
content at all. The expansion histories in two such frameworks are tested with data from type Ia
supernovae and measurements of the baryon acoustic peak in the galaxy distribution as well as in
the cosmic microwave background.
The second type of study concerns the possibility of establishing the particle nature of dark
matter through interactions other than gravitational. While there are ways of doing this using
astrophysical observations, the uncertainties due to astrophysics and the unknown distribution of
the dark matter are large. High energy particle colliders provide a way of imitating the conditions
of the early universe in the laboratory, where we can hope to produce yet unknown heavy particle
states and in a more controlled environment determine their properties. We study the prospects for
discovering two types of weakly interacting dark matter candidates at the CERN Large Hadron
Collider.
