Gauge invariance beyond the electric dipole approximation

Neutron Electric Dipole Moment in the Gauge-Higgs Unification

We study the neutron electric dipole moment (EDM) in a five dimensional SU(3) gauge-Higgs unification compactified on M × S/Z2 space-time including a massive fermion. We point out that to realize the CP violation is a non-trivial task in the gauge-Higgs unification scenario and argue how the CP symmetry is broken spontaneously by the VEV of the Higgs, the extra space component of the gauge fiel...

Interparticle force in polydisperse electrorheological fluids: Beyond the dipole approximation

We have developed a multiple image method to compute the interparticle force for a polydisperse electrorheological (ER) fluid. We apply the formalism to a pair of dielectric spheres of different dielectric constants and calculate the force as a function of the separation. The results show that the point-dipole (PD) approximation errs considerably because many-body and multipolar interactions ar...

Appearance of Gauge Fields and Forces beyond the adiabatic approximation

Perturbations of spacetime: gauge transformations and gauge invariance at second order and beyond

We consider in detail the problem of gauge dependence that exists in relativistic perturbation theory, going beyond the linear approximation and considering second and higher order perturbations. We first derive some mathematical results concerning the Taylor expansion of tensor fields under the action of one-parameter families (not necessarily groups) of diffeomorphisms. Second, we define gaug...

The Muon Electric Dipole Moment

The electric dipole moment of the muon (dμ) is evaluated in a two Higgs doublet model with a softly broken discrete symmetry. For tan β ≡ |v2|/|v1| ∼ 1, contributions from two loop diagrams involving the t quark and the W boson dominate; while for tan β ∼ > 10, contributions from two loop diagrams involving the b quark and the τ lepton are dominant. For 8 ∼ > tan β ∼ > 4, significant cancellati...