Theoretical Particle Physics The Johns Hopkins Theory Group consists of Professors Bagger, Domokos, Falk, Kaplan, Kovesi-Domokos, and Sundrum. It is studying a variety of phenomena related to Higgs bosons, Supersymmetry, Extra Dimensions, and Cosmology. Modern string theory employs warped (highly curved) compactifications of higher-dimensional spacetime. Such compactifications generate large geometrically-induced hierarchies via the Randall-Sundrum mechanism. They were originally applied to the hierarchy between the Planck and electroweak scales. The group is developing promising new classes of models that incorporate warped extra dimensions. One example is shown below: The group is investigating the broad range of phenomenology that arise in such models. The extra-dimensional profiles of elementary particles in warped geometries determine many properties of the Standard Model in an attractive way. The setup gives a consistent and coherent interpretation of known Standard Model phenomenology, including         -        Electroweak symmetry breaking and Higgs physics         -        Precision electroweak experiments         -        Quark and lepton masses and mixings         -        Flavor-changing rare processes         -        Coupling constant unification (as shown below) This class of models also provides predictions for ongoing and future experiments, including         -        The Tevatron and the CERN Large Hadron Collider         -        The KEK and SLAC B Factories         -        Dark matter detection experiments         -        The proposed International Linear Collider The AdS/CFT correspondence provides alternative description of this physics in terms of four-dimensional strong dynamics. It is being used to provide insight into and control over the physics from each point of view.