Constraints on Dark Energy Models from Galaxy Clusters and Gravitational Lensing Data

Abstract

Abstract:The Sunyaev-Zel'dovich (SZ) effect is a global distortion of the Cosmic Microwave Background (CMB) spectrum as a result of its interaction with a hot electron plasma in the intracluster medium of large structures gravitationally viralized such as galaxy clusters (GC). Furthermore, this hot gas of electrons emits X-rays due to its fall in the gravitational potential well of the GC. The analysis of SZ and X-ray data provides a method for calculating distances to GC at high redshifts. On the other hand, many galaxies and GC produce a Strong Gravitational Lens (SGL) effect, which has become a useful astrophysical tool for cosmology. We use these cosmological tests in addition to more traditional ones to constrain some alternative dark energy (DE) models, including the study of the history of cosmological expansion through the cosmographic parameters. Using Akaike and Bayesian Information Criterion, we find that the wCDM and ΛCDM models are the most favoured by the observational data. In addition, we found at low redshift a peculiar behavior of slowdown of the universe, which occurs in dynamical DE models when we use data from GC.

An improved model-independent assessment of the late-time cosmic expansion

“…Slowing down of the cosmic acceleration has been an issue of interest in several works [87][88][89][90][91][92]. In [87] this phenomenon was studied also utilising the Om(z) diagnostic, which suggests that an increase in Om(z) at lower redshift can indicate a slowing of acceleration.…”

Scrutinizing various phenomenological interactions in the context of holographic Ricci dark energy models

“…The value of the depletion component of the bias factor related to the gas dynamical simulation from fgas (gas mass fraction) data has been obtained b f gas = 0.824 +0.033 −0.033 [110]. This value has been used in some works as a fixed value [108,111,112]. We found that fixing this parameter strongly affects the values of other parameters and the value of χ 2 as well.…”

Classical and Quantum f(R) Cosmology: The Big Rip, the Little Rip and the Little Sibling of the Big Rip

“…Hence, observational constraints on w are crucial to unveil possible hints on the true nature of this exotic content. In this fashion, the cosmological data currently available constrain w to a very narrow band around −1 [37,38], see also [39][40][41][42][43][44][45]. Accordingly, the possibility of the expansion of the universe being fueled by phantom-type DE (w < −1) is not observationally excluded.…”

“…Note that the BR model here considered is just a subcase of the more general wCDM scenario, which has been thoroughly analyzed in the literature (see, for example, references [37][38][39][40][41][42][43][44][45], among others). More importantly, these specific phantom DE models have been shown to be compatible with the current observational data; see, for instance, references [37][38][39]51,56,57,79].…”