Hidden invariance in Gurzadyan-Xue cosmological models

Abstract

The dark energy formula derived by Gurzadyan and Xue which leads to a value fitting the SN data, provides a scaling relation between the physical constants and cosmological parameters and defines a set of cosmological models. In previous works we have considered several of those models and derived the cosmological equations for each case. In this letter, we present the phase portrait analysis of those models. Surprisingly we found, first, that the separatrix in the phase space which determines the character of solutions depends solely on the value of the current matter density. Namely, at ${\Omega }_m>2/3$ the equations describe Friedmannian Universe with the classical singularity at the beginning. While at ${\Omega }_m<2/3$ all solutions for all models start with zero density and non vanishing scale factor. Secondly, more remarkable, the value ${\Omega }_{sep}=2/3$ defining the separatrix is the same for all models, which reveales an underlying invariance hidden in the models, possibly, due to the basic nature of the GX-scaling.

to appear in Physics Letters B

References in corpus (3)

• Vacuum Fluctuations of Energy Density can lead to the observed Cosmological Constant
• Constraints on the Variation of G from Primordial Nucleosynthesis
• Physical constants and the Gurzadyan-Xue formula for the dark energy

Cited by in corpus (9)

• $\Lambda$-CDM Universe: A Phenomenological Approach With Many Possibilities
• Ellipticity in Cosmic Microwave Background as a Tracer of Large-Scale Universe
• Cosmological models with Gurzadyan-Xue dark energy
• Dark Energy From Vacuum Fluctuations
• Hubble Diagram of Gamma-Rays Bursts calibrated with Gurzadyan-Xue Cosmology
• Scenario of Accelerating Universe from the Phenomenological Λ- Models
• Invariants and solutions of Gurzadyan-Xue dark energy cosmological models
• Dynamics of perturbations in Gurzadyan-Xue cosmological models
• The Djorgovski-Gurzadyan dark energy integral equation and the Hubble diagram