Related papers: Dark Energy from Brane-world Gravity
We studied the dilaton cosmology based on Weyl-Scaled induced gravity. The potential of dilaton field is taken as exponential form. An analytical solution of Einstein equation is found. The dilaton can be a candidate for dark energy that…
The recent type Ia supernova data suggest that the universe is accelerating now and decelerated in recent past. This may provide the evidence that the standard Friedmann equation needs to be modified. We analyze in detail a new model in the…
The most studied way to explain the current accelerated expansion of the universe is to assume the existence of dark energy; a new component that fill the universe, does not clumps, currently dominates the evolution, and has a negative…
The quasi-static solutions of the matter density perturbation in various dark energy models and modified gravity models have been investigated in numerous papers. However, the oscillating solutions in those models have not been investigated…
Some models of modified gravity and their observational manifestations are considered. It is shown, that gravitating systems with mass density rising with time evolve to a singular state with infinite curvature scalar. The universe…
In this presentation prepared for a general audience, we briefly mention the shortcomings of standard model of universe. We then focus on the late time inconsistency of the model dubbed age crisis whose resolution requires the presence of a…
We briefly review the problems and prospects of the standard lore of dark energy and notice that the cosmological constant problems are often over emphasized. In order to keep the discussion pedagogical aimed at a wider audience, we have…
Major observational efforts in the coming decade are designed to probe the equation of state of dark energy. Measuring a deviation of the equation-of-state parameter w from -1 would indicate a dark energy that cannot be represented solely…
The role of brane-bulk energy exchange and of an induced gravity term on a single braneworld of negative tension and vanishing effective cosmological constant is studied. It is shown that for the physically interesting cases of dust and…
A six parameter cosmological model, involving a vacuum energy density that is extremely tiny compared to fundamental particle physics scales, describes a large body of increasingly accurate astronomical data. In a first part of this brief…
The discovery of the accelerating universe in the late 1990s was a watershed moment in modern cosmology, as it indicated the presence of a fundamentally new, dominant contribution to the energy budget of the universe. Evidence for dark…
The expansion of the Universe is accelerated as testified by observations of SNeIa at varying redshifts. Explanations of this acceleration are of two kinds: modifications of Einstein gravity or new forms of energy. An example of modified…
Cosmic acceleration is explained quantitatively, as an apparent effect due to gravitational energy differences that arise in the decoupling of bound systems from the global expansion of the universe. "Dark energy" is a misidentification of…
In the braneworld scenario, the four dimensional effective Einstein equation has extra terms which arise from the embedding of the 3-brane in the bulk. We show that in this modified theory of gravity, it is possible to model observations of…
Mounting observational data confirm that about 73% of the energy density consists of dark energy which is responsible for the current accelerated expansion of the Universe. We present observational evidences and dark energy projects. We…
By relaxing the conventional assumption of a purely gravitational interaction between dark energy and dark matter, substantial alterations to the growth of cosmological structure can occur. In this work we focus on the homogeneous transfer…
We review the accelerating (mainly, dark energy) cosmologies in modified gravity. Special attention is paid to cosmologies leading to finite-time future singularities in $F(R)$, $F(G)$ and $\mathcal{F}(R,G)$ modified gravities. The removal…
It is obtained that dark energy emerges from higher-derivative gravity with anon-linear terms proportional to $R^2$ and $R^3$ with $R$ being the Ricci scalar curvature. Interestingly, it is found that the universe begins with acceleration,…
The usual brane world scenario with anti de Sitter bulk has been generalized by considering a general form of energy momentum tensor in the bulk. The modified Einstein equation on the brane has been constructed. Two examples have been cited…
We argue that dark energy with multiple fields is theoretically well-motivated and predicts distinct observational signatures, in particular when cosmic acceleration takes place along a trajectory that is highly non-geodesic in field space.…