Related papers: Dynamical Systems Analysis of Various Dark Energy …
We investigate whether the recent DESI DR2 measurements provide or not evidences for dynamical dark energy by exploring the $\omega_0\omega_a$CDM model and its extensions with free $\sum m_{\nu}$ and $N_{\mathrm{eff}}$. Using a…
We investigate a link between the running of the fine structure constant $\alpha$ and a time evolving scalar dark energy field. Employing a versatile parameterization for the equation of state, we exhaustively cover the space of dark energy…
We investigated the stability of the chameleon screening mechanism in the Brans-Dicke scalar-tensor model. We define a constraint on the Brans-Dicke parameter $\omega_{BD}^*$ identifying two stability groups, $\omega_{BD}>\omega_{BD}^*$ and…
We give a scalar field description of two dark energy parameterizations, and we analyze in detail its cosmology both at the level of background evolution and at the level of linear perturbations. In particular, we compute the statefinder…
We extend the investigation of cosmological dynamics of the general non-canonical scalar field models by dynamical system techniques for a broad class of potentials and coupling functions. In other words, we do not restrict the analysis to…
Models where Dark Matter and Dark Energy interact with each other have been proposed to solve the coincidence problem. We review the motivations underlying the need to introduce such interaction, its influence on the background dynamics and…
In the proposed model with interaction between dark energy and dark matter, we consider cosmological scenarios with different equations of state ($w_d$) for dark energy. For both constant and variable equation of state, we analyze solutions…
Holographic principles have proven to be a very interesting approach towards dealing with the issues of the late-time acceleration of the universe, which has resulted in a great amount of work on holographic dark energy models. We consider…
Recent analyses from the DESI collaboration suggest that the dark energy density of the Universe may be decreasing with time, slowing the acceleration of the scale factor $a$. Typically these studies are performed assuming an ansatz for the…
We review the problem of dark energy, including a survey of theoretical models and some aspects of numerical studies.
We numerically and analytically explore the background cosmological dynamics of multifield dark energy with highly nongeodesic or "spinning" field-space trajectories. These extensions of standard single-field quintessence possess appealing…
We explore the scalar field quintessence freezing model of dark energy with the inverse Ratra-Peebles potential. We study the cosmic expansion and the large scale structure growth rate. We use recent measurements of the growth rate and the…
We examine the evolution of a holographic cosmological model with future event horizon as the infrared cut-off and dark matter and dark energy do not evolve independently $-$ there is interaction between them. The basic evolution equations…
Since the number of dark energy models have rapidly increased over the last years, some model-independent methods have been developed in order to analyse the cosmological evolution in a phenomenological way. In this manuscript, we analyse…
We use linear perturbation theory to study perturbations in dynamical dark energy models. We compare quintessence and tachyonic dark energy models with identical background evolution. We write the corresponding equations for different…
We present a general analytical treatment of cosmological models commanded by three interactive fluids with arbitrary barotropic indexes. The variable equations of state case are applicable to universes with quintessences, k essences and…
A five-dimensional cosmological model including a single perfect fluid is studied in the framework of dynamical system analysis. All the critical points of the system with their stability properties are listed and some representative phase…
We consider scalar field models of dark energy interacting with dark matter through a coupling proportional to the contraction of the four-derivative of the scalar field with the four-velocity of the dark matter fluid. The coupling is…
In this paper, the model of holographic Chaplygin gas has been extended to two general cases: first is the case of modified variable Chaplygin gas and secondly of the viscous generalized Chaplygin gas. The dynamics of the model are…
A huge amount of good quality astrophysical data converges towards the picture of a spatially flat universe undergoing the today observed phase of accelerated expansion. This new observational trend is commonly addressed as Precision…