Phenomenological Dark Energy model with hybrid dynamic Cosmological Constant

Abstract

We investigate Dark Energy by associating it with vacuum energy or Cosmological constant $\Lambda$ which is taken to be dynamic in nature. Our approach is phenomenological and falls within the domain of variable-$\Lambda$ Cosmology. However, motivated by quantum theory of metastable vacuum decay, we proposed a new phenomenological decay law of $\Lambda$(t) where $\Lambda$(t) is a superposition of constant and variable components viz. $\Lambda$(t) = ${\Lambda }_C$ + ${\Lambda }_v$ which is indicated by the word $"$hybrid dynamic$"$ in the title. By taking a simplified two-fluid scenario with the Universe consisting of Dark Energy and another major component, we found the solutions for three particular phenomenological expressions and made a parametrization of the model in terms of dilution parameter (the dilution parameter has been defined in the text as the exponent of scale factor in the expression of density of the other major component, representing the dilution of the component with the expansion of Universe in the presence of dynamic Dark Energy). For pressureless Dust and dynamic Dark Energy Universe, we found the present-day matter density (${\Omega }_{m0}$) and dilution parameter (u) to be ${\Omega }_{m0}$ = 0.29 $\pm$ 0.03, u = 2.90 $\pm$ 0.54 at 1 $\sigma$ by analysing 580 supernova from Union 2.1 catalogue. The physical features of the model in regard to scale factor evolution, deceleration parameter, cosmic age has also been studied and parallels have been drawn with $\Lambda$CDM model. The status of Cosmological problems in the model has also been checked which showed that the model solves the Cosmological Constant Problem but the Coincidence problem still exists in the model.

arXiv commentAccepted Manuscript version

References in corpus (33)

• Observational Evidence from Supernovae for an Accelerating Universe and a Cosmological Constant
• Measurements of Omega and Lambda from 42 High-Redshift Supernovae
• emcee: The MCMC Hammer
• The Cosmological Constant and Dark Energy
• Nine-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Parameter Results
• The Case for a Positive Cosmological Lambda-term
• The Complete Light-curve Sample of Spectroscopically Confirmed Type Ia Supernovae from Pan-STARRS1 and Cosmological Constraints from The Combined Pantheon Sample
• Large Magellanic Cloud Cepheid Standards Provide a 1% Foundation for the Determination of the Hubble Constant and Stronger Evidence for Physics Beyond LambdaCDM
• The Hubble Space Telescope Cluster Supernova Survey: V. Improving the Dark Energy Constraints Above z>1 and Building an Early-Type-Hosted Supernova Sample
• The Carnegie-Chicago Hubble Program. VIII. An Independent Determination of the Hubble Constant Based on the Tip of the Red Giant Branch
• Evolution of the Scale Factor with a Variable Cosmological Term
• Correcting Type Ia Supernova Distances for Selection Biases and Contamination in Photometrically Identified Samples
• Can vacuum decay in our Universe?
• Cosmology with a stiff matter era
• Can Late Dark Energy Transitions Raise the Hubble constant?
• Thermodynamics of Decaying Vacuum Cosmologies
• Alternative Dark Energy Models: An Overview
• A Machian Model of Dark Energy
• Phantom dark energy with varying-mass dark matter particles: acceleration and cosmic coincidence problem
• Quantifying concordance of correlated cosmological data sets
• Dark Matter with Time-Dependent Mass
• Spectral energy distributions and age estimates of 104 M31 globular clusters
• Power-law cosmology, SN Ia, and BAO
• Spectral Energy Distributions and Age Estimates of 39 Globular Clusters in M31
• Solving the main cosmological puzzles with a generalized time varying vacuum energy
• Dark-Energy Dynamics Required to Solve the Cosmic Coincidence
• Decay of the vacuum energy into CMB photons
• Cosmological models with Gurzadyan-Xue dark energy
• The evolution of the FRW universe with decaying metastable dark energy --- a dynamical system analysis
• Gravitationally induced particle production and its impact on structure formation
• Scenario of Accelerating Universe from the Phenomenological Λ- Models
• Generalized phenomenological models of dark energy
• New Globular Cluster Age Estimates and Constraints on the Cosmic Equation of State and The Matter Density of the Universe

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