Related papers: A Cosmic Vision Beyond Einstein
A simple description of the vacuum energy (cosmological constant) problem for non-experts is presented. Basic features of cosmology with non-zero vacuum energy are discussed. The astronomical data which indicate that the universe is filled…
There has been significant recent progress in observational cosmology. This, in turn, has provided an unprecedented picture of the early universe and its evolution. In this review I will present a (biased) view of how one can use these…
The present status of our knowledge about the dark matter and dark energy is reviewed. Bounds on the content of cold and hot dark matter from cosmological observations are discussed in some detail. I also review current bounds on the…
The discovery of dark energy (DE) as the physical cause for the accelerated expansion of the Universe is the most remarkable experimental finding of modern cosmology. However, it leads to insurmountable theoretical difficulties from the…
Under the assumption that General Relativity (GR) correctly describes the phenomenology of our Universe, astronomical observations provide compelling evidence that (1) the dynamics of cosmic structure is dominated by dark matter (DM), an…
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…
The most important problem in fundamental physics is the description of the contents of the Universe. Today, we know that 95% thereof is totally unknown. Two thirds of that amount is the mysterious Dark Energy described in an interesting…
Late-time cosmology in the extended cuscuton theory is studied, in which gravity is modified while one still has no extra dynamical degrees of freedom other than two tensor modes. We present a simple example admitting analytic solutions for…
In 1998 astronomers discovered that the expansion of the universe is accelerating. Somehow, something must have made gravity repulsive on cosmological scales. This something was called dark energy; it is described by Einstein's cosmological…
We review the implications of modern higher-dimensional theories of gravity for astrophysics and cosmology. In particular, we discuss the latest developments of space-time-matter theory in connection with dark matter, particle dynamics and…
Astronomical observations indicate an accelerated cosmic expansion, the cause of which is explained by the action of `dark energy'. Here we show that in discrete expanding space-time, only a tiny fraction of the vacuum fluctuations can…
We present a brief review of various approaches to late time acceleration of universe. The cosmological relevance of scaling solutions is emphasized in case of scalar field models of dark energy. The underlying features of a variety of…
I review the current status of Big Bang Cosmology, with emphasis on current issues in dark matter, dark energy, and galaxy formation. These topics motivate many of the current goals of experimental cosmology which range from targeting the…
I present a brief overview of some exciting possibilities for physics Beyond the Standard Model. I include short discussions of neutrino physics, the strong CP problem and axions, GUTs, large and warped extra dimensions, Little Higgs models…
The cosmological constant problem is the principal obstacle in the attempt to interpret dark energy as the quantum vacuum energy. We suggest that the obstacle can be removed, i.e. that the cosmological constant problem can be resolved by…
The current standard cosmological model is constructed within the framework of general relativity with a cosmological constant $\Lambda$, which is often associated with dark energy, and phenomenologically explains the accelerated cosmic…
In the standard model of cosmology, the present evolution of the Universe is determined by the presence of two components of unknown nature. One of them is referenced as ``dark matter'' to justify the fact that it behaves cosmologically…
The current expansion of the Universe has been observed to be accelerating, and the widely accepted spatially-flat concordance model of general relativistic cosmology attributes this phenomenon to a constant dark energy, a cosmological…
I consider some of the issues we face in trying to understand dark energy. Huge fluctuations in the unknown dark energy equation of state can be hidden in distance data, so I argue that model-independent tests which signal if the…
It is argued that fluctuations of quantum fields in four-dimensional space do not give rise to dark energy, but are rather a negligible contribution to dark matter. By (relativistic) dark matter we mean that the relation between pressure…