Scherk-Schwarz twist in 5D conformal SUGRA

We reinterpret the Scherk-Schwarz (SS) boundary condition for SU(2)_R in a compactified five-dimensional (5D) Poincare supergravity in terms of the twisted SU(2)_U gauge fixing in 5D conformal supergravity. In such translation, only the compensator hypermultiplet is relevant to the SS twist, and various properties of the SS mechanism can be easily understood. Especially we show the equivalence between the SS twist and boundary constant superpotentials at the full supergravity level.Comment: 4 pages, no figure, talks given at SUSY 2006 (UC Irvine) and Summer Institute 2006 (POSTECH), to appear in Proceedings of SUSY06, the 14th International Conference on Supersymmetry and the Unification of Fundamental Interactions, UC Irvine, California, 12-17 June 200

Dynamical Radion Superfield in Five-dimensional Action

We clarify the radion superfield dependence of 5D N=1 superspace action. The radion is treated as a dynamical field and appears in the action with the correct mode function. Our derivation is systematic and based on the superconformal formulation of 5D supergravity. We can read off the couplings of the dynamical radion superfield to the matter superfields from our result. The correct radion mass can be obtained by calculating the radion potential from our superspace action.Comment: 5 pages, talks given by Y.Sakamura at PASCOS'05 (Geongju, Korea, May 30-June 4, 2005) and at SUSY'05 (Durham, U.K., July 18-23, 2005

Dynamical radion superfield in 5D action

We derive 5D N=1 superspace action including the radion superfield. The radion is treated as a dynamical field and identified as a solution of the equation of motion even in the presence of the radius stabilization mechanism. Our derivation is systematic and based on the superconformal formulation of 5D supergravity. We can read off the couplings of the dynamical radion superfield to the matter superfields from our result. The correct radion mass can be obtained by calculating the radion potential from our superspace action.Comment: 29 pages, no figures, LaTeX, some comments adde

Full diffeomorphism and Lorentz invariance in 4D N=1{\cal N}=1 superfield description of 6D SUGRA

We complete the four-dimensional ${\cal N}=1$ superfield description of six-dimensional supergravity. The missing ingredients in the previous works are the superfields that contain the sechsbein $e_4^{\;\;\underline{\nu}}$, $e_5^{\;\;\underline{\nu}}$, $e_\mu^{\;\;\underline{4}}$, $e_\mu^{\;\;\underline{5}}$ and the second gravitino. They are necessary to make the action invariant under the diffeomorphisms and the Lorentz transformations involving the extra dimensions. We find the corresponding superfield transformation laws, and show the invariance of the action under them. We also check that the resultant action reproduces the known superfield description of five-dimensional supergravity through the dimensional reduction.Comment: 45 pages, some comments adde

N=1 superfield description of vector-tensor couplings in six dimensions

We express supersymmetric couplings among the vector and the tensor multiplets in six dimensions (6D) in terms of N=1 superfields. The superfield description is derived from the invariant action in the projective superspace. The obtained expression is consistent with the known superfield actions of 6D supersymmetric gauge theory and 5D Chern-Simons theory after the dimensional reduction. Our result provides a crutial clue to the N=1 superfield description of 6D supergravity.Comment: 28 pages, v2:a reference adde