Gauging of Lorentz Group WZW Model by its Null Subgroup

We consider the standard vector gauging of Lorentz group $SO(3,1)$ WZW model by its non-semisimple null Euclidean subgroup in two dimensions $E(2)$. The resultant effective action of the theory is seen to describe a one dimensional bosonic field in the presence of external charge that we interpret it as a Liouville field. Gauging a boosted $SO(3)$ subgroup, we find that in the limit of the large boost, the theory can be interpreted as an interacting Toda theory. We also take the generalized non-standard bilinear form for $SO(3,1)$ and gauge both $SO(3)$ and $E(2)$ subgroups and discuss the resultant theories.Comment: 11 pages, LaTeX fil

On the Exceptional Gauged WZW Theories

We consider two different versions of gauged WZW theories with the exceptional groups and gauged with any of theirs null subgroups. By constructing suitable automorphism, we establish the equivalence of these two theories. On the other hand our automorphism, relates the two dual irreducible Riemannian globally symmetric spaces with different characters based on the corresponding exceptional Lie groups.Comment: 5 pages, LaTeX fil

Quantizing field theories in noncommutative geometry and the correspondence between anti de Sitter space and conformal field theory

By using the approach of non-commutative geometry, we study spinors and scalars on the two layers AdS$_{d+1}$ space. We have found that in the boundary of two layers AdS$_{d+1}$ space, by using the AdS/CFT correspondence, we have a logarithmic conformal field theory. This observation propose a way to get the quantum field theory in the context of non-commutative geometry.Comment: some minor typographical errors are corrected, to appear in Phys. Lett.

Scalar Electrodynamics in Framework of Randall-Sundrum Model

Considering the Randall-Sundrum background, we calculate the total cross-section for $\phi\phi ^\star \to G \gamma$ in the framework of the scalar electrodynamics.Comment: 10 pages, RevTex, axodraw.sty, more graviton modes considered, typos corrected, to appear in Phys. Lett.

Slicing and Brane Dependence of the (A)dS/CFT Correspondence

We investigate the slicing dependence of the relationship between conserved quantities in the (A)dS/CFT correspondence. Specifically, we show that the Casimir energy depends upon the topology and geometry of spacetime foliations of the bulk near the conformal boundary. We point out that the determination of the brane location in brane-world scenarios exhibits a similar slicing dependence, and we comment on this in the context of the AdS/CFT correspondence conjecture.Comment: latex, 6 pages, minor changes in wording, reference adde