Slinky evolution of domain wall brane cosmology

TL;DR

This paper introduces a novel brane cosmology model where the formation and evolution of the universe are driven by a symmetry breaking mechanism involving an initial symmetry between time and an extra spatial dimension, leading to a decaying cosmological constant.

Contribution

It proposes a new scenario with a symmetry-based formation of branes and cosmology, introducing slinky configurations with a decaying cosmological constant, and analyzes their physical viability.

Findings

Slinky configurations exhibit a decaying cosmological constant.

A simplified model with a constrained watershed is constructed.

Conditions for realistic cosmological evolution are discussed.

Abstract

Invoking an initial symmetry between the time $ t $ and some extra spatial dimension $ y $, we discuss a novel scenario where the dynamical formation of the 4-dim brane and its cosmological evolution are induced simultaneously by a common $ t<->y $ symmetry breaking mechanism. The local maximum of the underlying scalar potential is mapped onto a 'watershed' curve in the $ (t,y) $ plane; the direction tangent to this curve is identified as the cosmic time, whereas the perpendicular direction serves locally as the extra spatial dimension. Special attention is devoted to the so-called slinky configurations, whose brane cosmology is characterized by a decaying cosmological constant along the watershed curve. Such a slinky solution is first constructed within a simplified case where the watershed is constrained by $ y = 0 $. The physical requirements for a slinky configuration to generate a realistic model of cosmological evolution are then discussed in a more elaborated framework.