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We revisit a class of coupled dark energy models where dark energy interacts with dark matter via phenomenological energy exchange terms. We include the perturbation of the Hubble rate in the interaction term, which was absent in previous…
We investigate an extended cosmological model motivated by the asymptotic safety of gravitational field theory, in which the matter and radiation densities and the cosmological constant receive a correction parametrized by the parameters…
We test the dynamical dark-energy $w_0w_a$CDM (CPL) framework against $\Lambda$CDM using CMB anisotropies and lensing together with DESI DR2, SDSS-IV, transverse/angular BAO (BAOtr), and Cepheid-calibrated PantheonPlus SN~Ia data. CPL…
It has been theorized that Dynamical Dark Energy (DDE) could be a possible solution to the Hubble tension. To avoid the degeneracy between the Hubble parameter $H_0$ and the sound horizon scale $r_d$, in this article we use their…
While $\Lambda$CDM provides a good fit to cosmological data, it fails to address many of the outstanding questions in contemporary cosmology. Chief among these are the Hubble tension and the apparent dynamical nature of dark energy as…
We investigate the scenario of interacting dark energy through a detailed confrontation with various observational datasets. We quantify the interaction in a general way, through the deviation from the standard scaling of the dark matter…
The late-time acceleration of the universe remains one of the most significant open problems in modern cosmology. Modified gravity frameworks such as $f(T)$ gravity provide a geometric alternative to dark energy by attributing cosmic…
A flat Friedman-Roberson-Walker universe dominated by a cosmological constant ($\Lambda$) and cold dark matter (CDM) has been the working model preferred by cosmologists since the discovery of cosmic acceleration. However, tensions of…
Recent studies suggest that dark energy may be dynamical rather than being a mere cosmological constant $\Lambda$. In this work, we examine the viability of two physically well-motivated dynamical dark energy models -- holographic dark…
We investigate a phenomenological extension of the standard $\Lambda$CDM framework, the $\Omega_1\Omega_2$-$\Lambda$CDM model, in which the total energy density of the universe is expanded in powers of $1+z$. This parameterization recovers…
The Multi-coupled Dark Energy (McDE) scenario has been recently proposed as a specific example of a cosmological model characterized by a non-standard physics of the dark sector of the universe that nevertheless gives an expansion history…
In a previous work it was shown that by considering the quantum nature of the gravitational field mediator, it is possible to introduce the momentum energy of the graviton into the Einstein equations as an effective cosmological constant.…
We investigate the impacts of dark energy on constraining massive (active/sterile) neutrinos in interacting dark energy (IDE) models by using the current observations. We employ two typical IDE models, the interacting $w$ cold dark matter…
Few phenomenological models tend to favour higher values of the Hubble parameter, often at the expense of invoking phantom transitions. These models achieve this without introducing additional parameters, akin to the simplicity of the…
We propose a new dark energy (DE) model from four parameter generalized entropy function of apparent horizon in a spatially flat universe. Such kind of generalized entropy is able to generalize all the known entropies proposed so far, for…
We present updated constraints on cosmological parameters in a 12-parameter model, extending the standard six-parameter $\Lambda$CDM by including dynamical dark energy (DE: $w_0$, $w_a$), the sum of neutrino masses ($\sum m_{\nu}$), the…
The DESI Collaboration reports a significant preference for a dynamic dark energy model ($w_0w_a$CDM) over the cosmological constant ($\Lambda$CDM) when their data are combined with other frontier cosmological probes. We present a direct…
We assess the consistency of cosmological models that alter the size of the sound horizon at last scattering to resolve the Hubble tension with data from ACT + Planck CMB lensing, Big Bang Nucleosynthesis, and supernova data from Pantheon…
We present updated observational constraints on the spatially flat $\phi$CDM model, where dark energy is described by a minimally coupled scalar field $\phi$ with an inverse power-law potential $V=V_0 \phi^{-\alpha}$. Using Planck 2018 CMB…
We consider the $f\left( Q\right) $-theory for the description of dark energy with a non-trivial connection defined in the non-coincident gauge. The resulting field equations form a two-scalar-field, quintom-like gravitational model. For…