Related papers: The CMB spectrum in Cardassian models
A new phenomenological dark energy model, originally associated to the large-scale structure formation and considered as a solution to the fine-tuning and coincidence problems related to the cosmological constant, was analyzed within the…
We calculate the angular scale of the acoustic oscillation from the BOOMERANG and WMAP data on the cosmic microwave background (CMB) to constrain the holographic dark energy model recently proposed by Li. We find that only the phantom-like…
The coupling between the dark components provides a new approach to mitigate the coincidence problem of cosmological standard model. In this paper, dark energy is treated as a fluid with a constant equation of state, whose coupling with…
We employ the Planck 2013 CMB temperature anisotropy and lensing data, and baryon acoustic oscillation (BAO) data to constrain a phenomenological $w$CDM model, where dark matter and dark energy interact. We assume time-dependent equation of…
In this study, we will look at an interacting dark energy model. In the framework of Friedmann-Robertson-Walker (FRW) space-time, we have made the hypothesis of an interacting scheme between two fields (dark matter (DM) and dark energy…
A suitable nonlinear interaction between dark matter with an energy density $\rho_{M}$ and dark energy with an energy density $\rho_{X}$ is known to give rise to a non-canonical scaling $\rho_{M} \propto \rho_{X}a^{-\xi}$ where $\xi$ is a…
We update a previous investigation of cosmological effects of a non-standard interaction between neutrinos and dark matter. Parameterizing the elastic-scattering cross section between the two species as a function of the temperature of the…
We have investigated the constraints on the Cardassian model using the recent results from the Wilkinson Microwave Anisotropy Probe (WMAP) for the locations of the peaks of the Cosmic Microwave Background (CMB) anistropy spectrum. We find…
We investigate the global dynamics of the universe within the framework of the Interacting Dark Matter (IDM) scenario. Considering that the dark matter obeys the collisional Boltzmann equation, we can obtain analytical solutions of the…
Creation of Cold Dark Matter (CCDM), in the context of Einstein Field Equations, leads to a negative creation pressure, which can be used to explain the accelerated expansion of the Universe. Recently, it has been shown that the dynamics of…
The dimming of Type Ia supernovae could be the result of Hubble-scale inhomogeneity in the matter and spatial curvature, rather than signaling the presence of a dark energy component. A key challenge for such models is to fit the detailed…
One of the principal discoveries in modern cosmology is that standard model particles (including baryons, leptons and photons) together comprise only 5% of the mass-energy budget of the Universe. The remaining 95% consists of dark energy…
Dark energy is modelled by a Bose-Einstein gas of particles with an attractive interaction. It is coupled to cold dark matter, within a flat universe, for the late-expansion description, producing variations in particle-number densities.…
In this paper, we revisit the Cardassian model in which the radiation energy component is included. It is important for early epoch when the radiation cannot be neglected because the equation of state (EoS) of the effective dark energy…
The fine-structure constant, $\alpha$, controls the strength of the electromagnetic interaction. There are extensions of the standard model in which $\alpha$ is dynamical on cosmological length and time-scales. The physics of the cosmic…
Models in which dark energy interacts with dark matter have been proposed in the literature to help explain why dark energy should only come to dominate in recent times. In this paper, we present a dynamical framework to calculate…
In this work we model two non-linear directly interacting scenarios in dark sector of the universe with the dimensionless parameter $\alpha$ and $\beta$, which dominate the energy exchange between dark energy and dark matter. The central…
Through analytic techniques verified by numerical calculations, we establish general relations between the matter and cosmic microwave background (CMB) power spectra and their dependence on cosmological parameters on small scales.…
The Hubble Constant measured from the anisotropy in the cosmic microwave background (CMB) is shown to be independent of small changes from the standard model of the redshift dependence of dark energy. Modifications of the Friedmann equation…
Recently the Chiral Cosmological Model (CCM) coupled to cold dark matter (CDM) has been investigated as $\sigma$CDM model to study the observed accelerated expansion of the Universe. Dark sector fields (as Dark Energy content) coupled to…