Related papers: Dark Energy as an Inverse Problem
Determination of the expansion and acceleration history of the universe is one of the fundamental goals of cosmology. Detailed measurements of these rates as a function of redshift can provide new physical insights into the nature and…
We present cosmological constraints from the sample of Type Ia supernovae (SN Ia) discovered during the full five years of the Dark Energy Survey (DES) Supernova Program. In contrast to most previous cosmological samples, in which SN are…
From recent CMB and Large Scale Structure observations the value of the equation of state of dark energy, assuming it to be constant in time, is constrained to be -1.3<w<-0.7 at the 95% confidence level: consistent with dark energy being a…
We extend and apply a model-independent analysis method developed earlier by Daly & Djorgovski to new samples of supernova standard candles, radio galaxy and cluster standard rulers, and use it to constrain physical properties of the dark…
In this work, we present a cosmological model in which the cosmological constant term is replaced by the Kretschmann scalar at the level of the action. In this way, it becomes possible to implement a model of dynamical dark energy. After…
We develop a formalism to characterize the redshift evolution of the dark energy potential. Our formalism makes use of quantities similar to the Horizon-flow parameters in inflation and is general enough that can deal with multiscalar…
The interacting dark energy model could propose a effective way to avoid the coincidence problem. In this paper, dark energy is taken as a fluid with a constant equation of state parameter $w_x$. In a general gauge, we could obtain two sets…
We investigate theoretical and observational aspects of a time-dependent parameterization for the dark energy equation of state (EoS) $w(z)$, which is a well behaved function of the redshift $z$ over the entire cosmological evolution, i.e.,…
A new method to investigate a possible time-dependence of the dark energy equation of state $w$ is proposed. We apply this methodology to two of the most recent data sets of type Ia supernova (Union2 and SDSS) and the baryon acoustic…
The formalism in order to obtain the Dark Energy equation of state is extended to non-flat universes and we consider the inequalities that must be satisfied by Phantom Dark Energy in this case. We show that due to a non-vanishing spatial…
The dark energy component of the universe still remains as a mystery, however, several papers based on observational data have shown that its equation of state may have an oscillatory behaviour. In this paper, we provide a general…
The presence of dark energy in the Universe is inferred directly from the accelerated expansion of the Universe, and indirectly, from measurements of cosmic microwave background (CMB) anisotropy. Dark energy contributes about 2/3 of the…
We show that an interaction between dark matter and dark energy generically results in an effective dark energy equation of state of w<-1. This arises because the interaction alters the redshift-dependence of the matter density. An observer…
A new parameterization for the dark energy equation of state(EoS) is proposed and some of its cosmological consequences are also investigated. This new parameterization is the modification of Efstathiou' dark energy EoS parameterization. $w…
We consider a model-independent approach to constrain the equivalence redshift, $z_{eq}$, at which dark energy and the total matter (cold dark matter and baryonic) equate their magnitudes. To this aim, in the context of a homogeneous and…
We present a method to implement the idea of Jain & Taylor to constrain cosmological parameters with weak gravitational lensing. Photometric redshift information on foreground galaxies is used to produce templates of the mass structure at…
We study the integrated Sachs-Wolfe (ISW) effect using a model-independent parameterization of the dark energy equation of state. Cosmic variance severely restricts the class of models distinguishable from Lambda-CDM. In particular if the…
We assume the DE state equations w(a) = w_0+w_a(a_p-a), and study the dependence of the constraints on w_0 and w_a coefficients on the pivoting redshift 1+z_p=1/a_p. Coefficients are fitted to data including WMAP7, SNIa (Union 2.1), BAO's…
Dark energy is now one of the most important and topical problems in cosmology. The first step to reveal its nature is to detect the evolution of dark energy or to prove beyond doubt that the cosmological constant is indeed constant.…
Determining the mechanism behind the current cosmic acceleration constitutes a major question nowadays in theoretical physics. If the dark energy route is taken, this problem may potentially bring to light new insights not only in Cosmology…