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## Full-Text Articles in Physics

Kaluza-Klein Theory With Torsion Confined To The Extra-Dimension, Karthik H. Shankar, Kameshwar C. Wali

#### Kaluza-Klein Theory With Torsion Confined To The Extra-Dimension, Karthik H. Shankar, Kameshwar C. Wali

*Physics*

Here we consider a variant of the 5 dimensional Kaluza-Klein theory within the framework of Einstein-Cartan formalism that includes torsion. By imposing a set of constraints on torsion and Ricci rotation coefficients, we show that the torsion components are completely expressed in terms of the metric. Moreover, the Ricci tensor in 5D corresponds exactly to what one would obtain from torsion-free general relativity on a 4D hypersurface. The contributions of the scalar and vector elds of the standard K-K theory to the Ricci tensor and the affine connections are completely nulli ed by the contributions from torsion. As a consequence ...

Su(5) Grand Unification On A Domain-Wall Brane From An E_6-Invariant Action, Aharon Davidson, Damien P. George, Archil Kobakhidze, Raymond R. Volkas, Kameshwar C. Wali

#### Su(5) Grand Unification On A Domain-Wall Brane From An E_6-Invariant Action, Aharon Davidson, Damien P. George, Archil Kobakhidze, Raymond R. Volkas, Kameshwar C. Wali

*Physics*

An SU(5) grand unification scheme for effective 3+1-dimensional fields dynamically localised on a domain-wall brane is constructed. This is achieved through the confluence of the clash-of-symmetries mechanism for symmetry breaking through domain-wall formation, and the Dvali-Shifman gauge-boson localisation idea. It requires an E_6 gauge-invariant action, yielding a domain-wall solution that has E_6 broken to differently embedded SO(10) x U(1) subgroups in the two bulk regions on opposite sides of the wall. On the wall itself, the unbroken symmetry is the intersection of the two bulk subgroups, and contains SU(5). A 4+1-dimensional fermion family in ...

The Clash Of Symmetries In A Randall-Sundrum-Like Spacetime, Gareth Dando, Aharon Davidson, Damien P. George, Raymond R. Volkas, Kameshwar C. Wali

#### The Clash Of Symmetries In A Randall-Sundrum-Like Spacetime, Gareth Dando, Aharon Davidson, Damien P. George, Raymond R. Volkas, Kameshwar C. Wali

*Physics*

We present a toy model that exhibits clash-of-symmetries style Higgs field kink configurations in a Randall-Sundrum-like spacetime. The model has two complex scalar fields Phi_{1,2}, with a sextic potential obeying global U(1)xU(1) and discrete Phi_1Phi_2 interchange symmetries. The scalar fields are coupled to 4+1 dimensional gravity endowed with a bulk cosmological constant. We show that the coupled Einstein-Higgs field equations have an interesting analytic solution provided the sextic potential adopts a particular form. The 4+1 metric is shown to be that of a smoothed-out Randall-Sundrum type of spacetime. The thin-brane Randall-Sundrum limit, whereby ...

Domain Wall Solutions With Abelian Gauge Fields, J. S. Rozowsky, R. R. Volkas, K. C. Wali

#### Domain Wall Solutions With Abelian Gauge Fields, J. S. Rozowsky, R. R. Volkas, K. C. Wali

*Physics*

We study kink (domain wall) solutions in a model consisting of two complex scalar fields coupled to two independent Abelian gauge fields in a Lagrangian that has $U(1)\times U(1)$ gauge plus $\mathbb{Z}_2$ discrete symmetry. We find consistent solutions such that while the U(1) symmetries of the fields are preserved while in their respective vacua, they are broken on the domain wall. The gauge field solutions show that the domain wall is sandwiched between domains with constant magnetic fields.

Clash Of Symmetries On The Brane, Aharon Davidson, B. F. Toner, R. R. Volkas, K. C. Wali

#### Clash Of Symmetries On The Brane, Aharon Davidson, B. F. Toner, R. R. Volkas, K. C. Wali

*Physics*

If our 3 + 1-dimensional universe is a brane or domain wall embedded in a higher dimensional space, then a phenomenon we term the “clash of symmetries” provides a new method of breaking some continuous symmetries. A global

Gcts ⊗ Gdiscrete symmetry is spontaneously broken to Hcts ⊗ Hdiscrete, where the continuous subgroup Hcts can be embedded in several different ways in the parent group Gcts, and Hdiscrete < Gdiscrete. A certain class of topological domain wall solutions connect two vacua that are invariant under differently embedded Hcts subgroups. There is then enhanced symmetry breakdown to the intersection of these two subgroups on the domain wall.This is the “clash”. In the brane limit, we obtain a configuration with Hcts symmetries in the bulk but the smaller intersection symmetry on the brane itself. We illustrate this idea using a permutation symmetric three-Higgstriplet toy model exploiting the distinct I−, U− and V − spin U(2) subgroups of U(3). The three disconnected portions of the vacuum manifold can be treated symmetrically through the construction of a three-fold planar domain wall junction configuration, with our universe at the nexus. A possible con-

Light-Heavy Symmetry: Geometric Mass Hierarchy For Three Families, Aharon Davidson, Tomer Schwartz, Kameshwar C. Wali

#### Light-Heavy Symmetry: Geometric Mass Hierarchy For Three Families, Aharon Davidson, Tomer Schwartz, Kameshwar C. Wali

*Physics*

The Universal Seesaw pattern coupled with a Light

↔ Heavy symmetry principle leads to the Diophantine equation N =NXi =1ni, where ni ≥ 0 and distinct. Its unique non-trivial solution (3 = 0+1+2) gives rise to the geometric mass hierarchy mW, mWǫ, mWǫ2 for N = 3 fermion families. This is realized in a model where the hybrid (yet Up ↔ Down symmetric) quark mass relations m dmt ≈ m2 c ↔ mumb ≈ m2 s play a crucial role in expressing the CKM mixings in terms of simple mass ratios, notably sin θC ≈ m c m b . PACS numbers: 11.30.Hv, 12.10.Kt ...