Talk detail

MG15 - Talk detail

Back to previous page

 Participant

Slagter, Reinoud

Institution

Asfyon and Univ of A'dam  - Marielaan 16 - Bussum - Outside US - Netherland

Session

CS1

Accepted

Order

Time

Talk

Oral abstract

Title

Evidence of Cosmic Strings by the Observation of the Alignment of Quasar Polarization Axes on Mpc scale.
Coauthors

Abstract

The recently found alignment of the polarization axes of quasars in large quasar groups on Mpc scales, can be explained by general relativistic cosmic string networks. By considering the cosmic string as a result of spontaneous symmetry breaking of the gauged U(1) abelian Higgs model with topological charge $n$, many stability features of the $n$-vortex solutions of superconductivity can be taken over. Decay of the high multiplicity ($n$) super-conducting vortex into a lattice of $n$ vortices of unit magnetic flux is energetically favourable. The temporarily broken axial symmetry will leave an imprint of a preferred azimuthal-angle on the lattice. The stability of the lattice depends critically on the parameters of the model, especially when gravity comes into play.\\ In order to handle the strong nonlinear behavior of the time-dependent coupled field equations of gravity and the scalar-gauge field, we will use a high-frequency approximation scheme to second order on a warped 5D axially symmetric spacetime with the scalar-gauge field residing on the brane.\\ We consider different winding numbers for the subsequent orders of perturbations of the scalar field. \\ A profound contribution to the energy momentum tensor comes from the bulk spacetime and can be understand as "dark"-energy. The cosmic string becomes super-massive by the contribution of the 5D Weyl tensor on the brane and the stored azimuthal preferences will not fade away. During the recovery to axial symmetry, gravitational and electro-magnetic radiation will be released\\ The perturbative appearance of a non-zero energy-momentum component $T_{t\varphi}$ can be compared with the phenomenon of bifurcation along the Maclaurin-Jacobi sequence of equilibrium ellipsoids of self-gravitating compact objects, signaling the onset of secular instabilities. There is a kind of similarity with the Goldstone-boson modes of spontaneously broken symmetries of continuous groups. The recovery of the SO(2) symmetry from the equatorial eccentricity takes place on a time-scale comparable with the emission of gravitational waves.\\ The emergent azimuthal-angle dependency in our model can be used to explain the aligned polarization axes in large quasar groups on Mpc scales. Spin axis direction perpendicular to the major axes of large quasar groups when the richness decreases, can be explained as a second order effect in our approximation scheme by the higher multiplicity terms. The preferred directions are modulo $\frac{180^o}{i}$, with $i$ an integer dependent on the $i$-th order of approximation. \\ When more data of quasars of high redshift will become available, one could proof that the alignment emerged after the symmetry breaking scale and must have a cosmological origin. The effect of the warp factor on the second-order perturbations could also be an indication of the existence of large extra dimensions.

Pdf file

 

Session

ES3

Accepted

Order

Time

Talk

Oral abstract

Title

Warped 5D Cosmic Strings, Conformal Invariance and the Quasar Link
Coauthors

Abstract

Topological defects formed in the early stages of our universe can play a crucial role in understanding anisotropic deviations of the Friedmann Lema\^{\i}tre Robertson Walker model we observe today. These defects are the result of phase transitions associated with spontaneous symmetry breaking in gauge theories at the grand unification energy scale. The most interesting defects are cosmic strings, vortex-like structures in the famous gauged U(1) abelian Higgs model with a 'Mexican-hat" potential. Other defects, such as domain walls and monopoles are probably ruled out, because they should dominate otherwise the energy density of our universe. This local gauge model is the fundament of the standard model of particle physics, where the Higgs-mechanism provides elementary particles with mass. It cannot be a coincidence that this model also explains the theory of superconductivity. The decay of the high multiplicity ($n$) super-conducting vortex into a lattice of $n$ vortices of unit magnetic flux is energetically favourable and is experimentally confirmed. It explains the famous Meissner effect. This process could play a fundamental role by the entanglement of cosmic strings just after the symmetry breaking. The stability of the lattice depends critically on the parameters of the model, especially when gravity comes into play. The questions is how the imprint of the cosmic strings could be observed at present time. Up to now, no evidence is found. The recently found alignment of the spinning axes of quasars in large quasar groups on Mpc scales, could be a first indication of the existence of these cosmic strings. The temporarily broken axial symmetry will leave an imprint of a preferred azimuthal-angle on the lattice. This effect is only viable when a scaling factor is introduced. This can be realized in a warped five dimensional model. The warp factor plays the role of a dilaton field on an equal footing with the Higgs field. The resulting field equations can be obtained from a conformal invariant model. Conformal invariance, the missing symmetry in general relativity, will then spontaneously be broken, just as the Higgs field. The dilaton field, or equivalently, the warp factor, could also contribute to the expansion of the universe as it can act as a dark energy term coming from the bulk spacetime. It makes the cosmic string temporarily super-massive. This process could solve the cosmological constant and hierarchy problem. It is conjectured that the dilaton field has a dual meaning. At very early times, when the dilaton field approaches zero, it describes the small-distance limit of the model, while at later times it is a warp (or scale) factor that determines the dynamical evolution of the universe. When more data of quasars of high redshift will become available, one could proof that the alignment emerged after the symmetry breaking scale and must have a cosmological origin. The effect of the warp factor on the second-order perturbations could also be an indication of the existence of large extra dimensions.

Pdf file

 

Back to previous page