Related papers: Phantom Energy and Cosmic Doomsday
The discovery of accelerated cosmic expansion implies that, in addition to the attractive gravity of matter, there exists in our universe some other form of energy (dark energy or cosmological constant) producing a repulsive force. The…
Understanding gravitational collapse requires understanding how $\sim 10^{58}$ nucleons can be destroyed in $\sim 10^{-5}$ seconds. The recent proposal that the endpoint of gravitational collapse can be a "dark energy star" implies that the…
We extend the Loop Quantum Cosmology matter bounce scenario in order to include a dark energy era, which ends abruptly at a Rip singularity where the scale factor and the Hubble rate diverge. In the "deformed matter bounce scenario", the…
It is widely assumed that the observed universe is accelerating due to the existence of a new fluid component called dark energy. In this article, the thermodynamics consequences of a nonzero chemical potential on the dark energy component…
Dark energy is one of the mysteries of modern science. It is unlike any known form of matter or energy and has been detected so far only by its gravitational effect of repulsion. Owing to its effects being discernible only at very very…
Recently it was found, in a broad class of models, that the dark energy density may change its sign during the evolution of the universe. This may lead to a global collapse of the universe within the time t_c ~ 10^{10}-10^{11} years. Our…
To explain the acceleration of the cosmological expansion researchers have considered an unusual form of mass-energy generically called dark energy. Dark energy has a ratio of pressure over mass density which obeys $w=p/\rho <-1/3$. This…
In this letter we show that, at its fundamental level, phantom dark energy is a fluid made up of time crystals that permeate the fabric of space-time. In turn, any well-behaved stable theory of a non-canonical scalar field that acts as…
Considering that the universe is filled with the nonrelativistic matter and dark energy and each component is respectively satisfied with its conservation condition in the absence of their interaction, we give the change rate of the…
Dark energy with the usually used equation of state $p=w\rho$, where $w=const<0$ is hydrodynamically unstable. To overcome this drawback we consider the cosmology of a perfect fluid with a linear equation of state of a more general form…
We discuss the questions related to dark energy in the Universe. We note that in spite of the effect of dark energy, large-scale structure is still being generated in the Universe and this will continue for about ten billion years. We also…
In recent work, a new cosmological paradigm implied a mass-radius relation, suggesting a universal tension related to the background dark energy (cosmological constant), leading to an energy per unit area that holds for structures from…
The discovery that most of the energy density in the universe is stored in the form of dark energy has profound consequences for our future. In particular our current limited understanding of quantum theory of gravity indicates that some…
Recent observations confirm that our universe is flat and consists of a dark energy component $\Omega_{DE}\simeq 0.7$. This dark energy is responsible for the cosmic acceleration as well as determines the feature of future evolution of the…
Black holes are an apparently unavoidable prediction of classical General Relativity, at least if matter obeys the strong energy condition rho + 3p > 0. However quantum vacuum fluctuations generally violate this condition, as does the eq.…
We investigate several varying-mass dark-matter particle models in the framework of phantom cosmology. We examine whether there exist late-time cosmological solutions, corresponding to an accelerating universe and possessing dark energy and…
This paper contains a detailed discussion on new cosmic solutions describing the early and late evolution of a universe that is filled with a kind of dark energy that may or may not satisfy the energy conditions. The main distinctive…
Observations provide increasingly strong evidence that the universe is accelerating. This revolutionary advance in cosmological observations confronts theoretical cosmology with a tremendous challenge, which it has so far failed to meet.…
The fact that the energy densities of dark energy and matter are similar currently, known as the coincidence problem, is one of the main unsolved problems of cosmology. We present here a model in which a spatial curvature of the universe…
Dark energy and dark matter constitute 95% of the observable Universe. Yet the physical nature of these two phenomena remains a mystery. Einstein suggested a long-forgotten solution: gravitationally repulsive negative masses, which drive…