A New Fate of a Warped 5D FRW Model with a U(1) Scalar Gauge Field

TL;DR

This paper explores a warped 5D brane-world model with a U(1) scalar gauge field, revealing how cosmic strings and gravitational disturbances evolve differently from standard cosmology, potentially explaining large-scale cosmic alignments.

Contribution

It introduces a novel warped 5D brane-world scenario with a dynamic warp factor affecting cosmic string behavior and late-time universe evolution, not present in standard 4D models.

Findings

Branons can form dynamically due to modified energy-momentum tensor.

Late-time behavior deviates from standard cosmology, resembling dark energy effects.

Warp factor amplifies gravitational disturbances, possibly explaining cosmic quasar alignments.

Abstract

If we live on the weak brane with zero effective cosmological constant in a warped 5D bulk spacetime, gravitational waves and brane fluctuations can be generated by a part of the 5D Weyl tensor and carries information of the gravitational field outside the brane. We consider on a cylindrical symmetric warped FRW background the U(1) self-gravitating scalar-gauge field without bulk matter. It turns out that "branons" can be formed dynamically, due to the modified energy-momentum tensor components of the cosmic string. As a result, we find that the late-time behavior could be significant deviate from the standard evolution of the universe. The effect is triggered by the time-dependent warp factor, of the form $\sqrt{ae^{\tau t}+be^{-\tau t}}$ and the modified brane equations, comparable with a dark energy effect. This is a brane-world mechanism, not present is standard 4D FRW, where the large disturbances are rapidly damped as the expansion proceed. Because gravity can propagate in the bulk, the cosmic string can build up a huge angle deficit (or mass per unit length) by the warp factor. Disturbances in the spatial components of the stress-energy tensor cause cylindrical symmetric waves, amplified due to the presence of the bulk space and warpfactor. This long range effect could also explain the recently found spooky alignment of quasars in vast structures in the cosmic web.