Related papers: What is the Evidence for Dark Matter?
In this paper we review a part of the approaches that have been considered to explain the extraordinary discovery of the late time acceleration of the Universe. We discuss the arguments that have led physicists and astronomers to accept…
The non-Keplerian galactic rotational curves and the gravitational lensing data strongly indicate a significant dark matter component in the universe. Moreover, these data can be combined to deduce the equation of state of dark matter. Yet,…
Two interesting hypotheses about black holes have been proposed. The older one states that microscopic black holes can be accountable for the observed dark matter density. The newer one states that black holes are coupled to the expansion…
Reasons supporting the idea that most of the dark matter in galaxies and clusters of galaxies is baryonic are discussed. Moreover, it is argued that most of the dark matter in galactic halos should be in the form of MACHOs and cold…
The basic idea in this Letter is the assumption that masses of the galactic constituents (particles of short-living fluctuations) may be functions of strength of the gravitational field. They may be in galactic space heavier than in the…
Matter in the universe has become ``dark'' or ``missing'' through misconceptions about the fluid mechanics of gravitational structure formation. Gravitational condensation occurs on non-acoustic density nuclei at the largest Schwarz length…
Cosmological and astrophysical measurements indicate that the universe contains a large amount of dark matter. A number of weak scale dark matter candidates have been proposed in extensions of the standard model. The potential to discover…
The non-linear process of cosmic structure formation produces gravitationally bound overdensities of dark matter known as halos. The abundances, density profiles, ellipticities, and spins of these halos can be tied to the underlying…
Traditional evidence for large amount of dark matter is based on dynamical consideration for systems with $ t_{dyn} \gg t_{obs} $. Recent observational and theoretical developments in gravitational lensing offer a much more robust…
Over the past few decades, a consensus picture has emerged in which roughly a quarter of the universe consists of dark matter. I begin with a review of the observational evidence for the existence of dark matter: rotation curves of…
A wealth of astronomical data indicate the presence of mass discrepancies in the Universe. The motions observed in a variety of classes of extragalactic systems exceed what can be explained by the mass visible in stars and gas. Either (i)…
Dark matter is estimated to make up ~84% of all normal/baryonic matter, but cannot be directly imaged. Despite the fact that dark matter cannot be directly observed yet, its influence on the motion of stars and gas in spiral galaxies have…
Clusters of galaxies, being dark matter dominated, have long been and still are the ideal cosmological targets to study the nature of dark matter. Constraints on the nature of dark matter comes in particular from the observational…
Cold Dark Matter (CDM) has become the standard modern theory of cosmological structure formation. Its predictions appear to be in good agreement with data on large scales, and it naturally accounts for many properties of galaxies. But…
Although the theoretical understanding of the nonlinear gravitational clustering has greatly advanced in the last decades, in particular by the outstanding improvement on numerical N-body simulations, the physics behind this process is not…
Gravitational potentials in the cosmos are deeper than expected from observed visible objects, a phenomenon usually attributed to dark matter, presumably in the form of a new fundamental particle. Until such a particle is observed, the jury…
Experimental observations and theoretical arguments at Galaxy and larger scales have suggested that a large fraction of the Universe is composed by Dark Matter particles. This has motivated the DAMA experimental efforts to investigate the…
We attempt to answer whether neutrinos and antineutrinos, such as those in the cosmic neutrino background, would clusterize among themselves or even with other dark-matter particles, under certain time span, say 1 Gyr. With neutrino masses…
In this pedestrian approach I give my personal point of view on the various problems posed by dark matter in the universe. After a brief historical overview I discuss the various solutions stemming from high energy particle physics, and the…
The standard model of particle physics is marvelously successful. However, it is obviously not a complete or final theory. I shall argue here that the structure of the standard model gives some quite concrete, compelling hints regarding…