A possible connection between the dark matter and strong first order electroweak phase transition,
which is an essential ingredient of the electroweak baryogenesis, has been explored in this thesis.
It is shown that the extension of the Standard Model's minimal Higgs sector with an
inert SU(2)L scalar doublet can provide light dark matter candidate
and simultaneously induce a strong first order phase transition.
There is however no symmetry reason to prevent the
extension using scalars with higher SU(2)L representations. Therefore, by
making random scans over the models' parameters, we show,
in the light of electroweak physics constraints, strong first
order electroweak phase transition and the possibility of having a
sub-TeV cold dark matter candidate, that the
higher representations are rather disfavored compared to the inert
doublet. This is done by computing generic perturbativity
behavior and impact on electroweak phase transitions of higher
representations in comparison with the inert doublet model. Explicit
phase transition and cold dark matter phenomenology within the context
of the inert triplet and quartet representations are used for detailed
illustrations
