The idea of extra dimensions opens a new way to solve the gauge hierarchy problem---the large difference between the electroweak scale (~ 1TeV) and the Planck scale (10^16 TeV). The two famous models are the Arkani-Hamed-Dimopoulos-Dvali (ADD) braneworld model with large extra dimensions and the Randall-Sundrum one with warped extra dimension. In this talk we will introduce some new models that can also solve the gauge hierarchy problem but and predict new phenomenology. |