Bulk Higgs with 4D Gauge Interactions

We consider a model with an extra compact dimension in which the Higgs is a bulk field while all other Standard Model fields are confined on a brane. We find that four-dimensional gauge invariance can still be achieved by appropriate modification of the brane action. This changes accordingly the Higgs propagator so that, the Higgs, in all its interactions with Standard Model fields, behaves as an ordinary 4D field, although it has a bulk kinetic term and bulk self-interactions. In addition, it cannot propagate from the brane to the bulk and, thus, no charge can escape into the bulk but it remains confined on the brane. Moreover, the photon remains massless, while the dependence of the Higgs vacuum on the extra dimension induces a mixing between the graviphoton and the Z-boson. This results in a modification of the sensitive \rho-parameter.Comment: 16 page

Inflation and Conformal Invariance: The Perspective from Radial Quantization

According to the dS/CFT correspondence, correlators of fields generated during a primordial de Sitter phase are constrained by three-dimensional conformal invariance. Using the properties of radially quantized conformal field theories and the operator-state correspondence, we glean information on some points. The Higuchi bound on the masses of spin-s states in de Sitter is a direct consequence of reflection positivity in radially quantized CFT$_3$ and the fact that scaling dimensions of operators are energies of states. The partial massless states appearing in de Sitter correspond from the boundary CFT$_3$ perspective to boundary states with highest weight for the conformal group. We discuss inflationary consistency relations and the role of asymptotic symmetries which transform asymptotic vacua to new physically inequivalent vacua by generating long perturbation modes. We show that on the CFT$_3$ side, asymptotic symmetries have a nice quantum mechanics interpretation. For instance, acting with the asymptotic dilation symmetry corresponds to evolving states forward (or backward) in "time" and the charge generating the asymptotic symmetry transformation is the Hamiltonian itself. Finally, we investigate the symmetries of anisotropic inflation and show that correlators of four-dimensional free scalar fields can be reproduced in the dual picture by considering an isotropic three-dimensional boundary enjoying dilation symmetry, but with a nonvanishing vacuum expectation value of the boundary stress-energy momentum tensor.Comment: 41 pages, 4 figure

A canonical approach to S-duality in Abelian gauge theory

We examine the electric-magnetic duality for a U(1) gauge theory on a general 4-manifold. The partition function for such a theory transforms as a modular form of specific weight. However, in the canonical approach, we show that S-duality, like T-duality, is generated by a canonical transformation leading to a modular invariant partition function.Comment: latex, 10 page