Cyclic Magnetic Universe

TL;DR

This paper proposes a cyclic cosmological model driven by nonlinear magnetic fields, featuring phases of bouncing, expansion, acceleration, and re-collapse, suggesting a universe that undergoes infinite cycles due to electromagnetic invariance.

Contribution

It introduces a novel cyclic universe model based on nonlinear electrodynamics with magnetic fields, incorporating a re-bouncing phase after acceleration, extending previous NLED cosmology theories.

Findings

The universe undergoes a sequence of bouncing, expansion, acceleration, and re-collapse.

The model demonstrates invariance under a dual map of the scale factor and electromagnetic field.

The cyclic behavior can repeat indefinitely, forming a cyclic magnetic universe.

Abstract

Recent works have shown the important role Nonlinear Electrodynamics (NLED) can have in two crucial questions of Cosmology, concerning particular moments of its evolution for very large and for low-curvature regimes, that is for very condensed phase and at the present period of acceleration. We present here a toy model of a complete cosmological scenario in which the main factor responsible for the geometry is a nonlinear magnetic field which produces a FRW homogeneous and isotropic geometry. In this scenario we distinguish four distinct phases: a bouncing period, a radiation era, an acceleration era and a re-bouncing. It has already been shown that in NLED a strong magnetic field can overcome the inevitability of a singular region typical of linear Maxwell theory; on the other extreme situation, that is for very weak magnetic field it can accelerate the expansion. The present model goes one step further: after the acceleration phase the universe re-bounces and enter in a collapse era. This behavior is a manifestation of the invariance under the dual map of the scale factor $ a(t) \to 1/ a(t),$ a consequence of the corresponding inverse symmetry of the electromagnetic field ($ F \to 1/ F,$ where $F \equiv F^{\mu\nu}F_{\mu\nu}$) of the NLED theory presented here. Such sequence collapse-bouncing-expansion-acceleration-re-bouncing-collapse constitutes a basic unitary element for the structure of the universe that can be repeated indefinitely yielding what we call a Cyclic Magnetic Universe.