Topics in Higgs phenomenology and holographic complexity

This dissertation presents four sample work which are divided into two very distinct categories. The first category is particle phenomenology, for which I show a series of study on the Higgs potential effects. One effect is its vacuum stability, controlled by the renormalization group running of the Higgs self coupling. The other is the impact on baryogenesis from the electroweak phase transition. A scalar-assisted vector-like fermion model is used to study the two effects, and experimental constraints are found for this model. The second category is holography, or specifically the holographic complexity. Both the time dependence and the UV divergence structure for holographic complexity are investigated. The former is done for a class of finite temperature non-commutative field theory, where both late time behavior and finite time behavior are analysed. For the UV divergence structure study, we choose the 3D kink subregion on the boundary, which is the simplest subregion with singular surface. Properties of subregion complexity are examined.