Decaying Dark Energy in Light of the Latest Cosmological Dataset

Abstract

Decaying Dark Energy models modify the background evolution of the most common observables, such as the Hubble function, the luminosity distance and the Cosmic Microwave Background temperature-redshift scaling relation.We use the most recent observationally-determined datasets, including Supernovae Type Ia and Gamma Ray Bursts data, along with H(z) and Cosmic Microwave Background temperature versus z data and the reduced Cosmic Microwave Background parameters, to improve the previous constraints on these models. We perform a Monte Carlo Markov Chain analysis to constrain the parameter space, on the basis of two distinct methods. In view of the first method, the Hubble constant and the matter density are left to vary freely. In this case, our results are compatible with previous analyses associated with decaying Dark Energy models, as well as with the most recent description of the cosmological background. In view of the second method, we set the Hubble constant and the matter density to their best fit values obtained by the Planck satellite, reducing the parameter space to two dimensions, and improving the existent constraints on the model's parameters. Our results suggest that the accelerated expansion of the Universe is well described by the cosmological constant, and we argue that forthcoming observations will play a determinant role to constrain/rule out decaying Dark Energy.

Modified gravity revealed along geodesic tracks

“…the General Relativity) as compared to the up to the date prevailing one (Newtons). Similarly, many models which modify/extend General Relativity have been proposed to overcome the (arguably somewhat uncomfortable) need to introduce fluid/particle realizations of dark matter and dark energy [9,10,11,12,13,14,15,16,17,18,19,20,21,22,23].…”

Testing creation cold dark matter cosmology with the radiation temperature–redshift relation

“…However, the tiny value of the vacuum energy density associated with Λ (ρ v = Λ/8πG) is plagued with the cosmic coincidence and cosmological constant problems [1][2][3]. Such mysteries have inspired many cosmologists to propose alternative models based on rather different approaches [4,5], among them: modified gravity [6][7][8][9][10][11], quintessence [12][13][14][15], time-evolving Λ models [16][17][18][19], interaction between dark components [20][21][22][23][24][25] and gravitationally induced particle production or CCDM cosmology [26][27][28][29][30][31][32][33][34].…”

A Markov Switching Approach in Assessing Oil Price and Stock Market Nexus in the Last Decade: The Impact of the COVID-19 Pandemic

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