Related papers: Dark Matter Candidates
Astronomical observations in the electromagnetic window - microwave, radio and optical - have revealed that most of the Universe is dark. The only reason we know that dark matter exists is because of its gravitational influence on luminous…
The standard theory of galaxy formation predicts that all galaxies should contain dark matter, yet a handful of recently discovered galaxies appear to lack it, challenging our understanding of galaxy formation. We investigate whether such…
A web of interlocking observations has established that the expansion of the Universe is speeding up and not slowing, revealing the presence of some form of repulsive gravity. Within the context of general relativity the cause of cosmic…
The emerging cosmological picture is of a spatially flat universe composed predominantly of three components: ordinary baryons ($\Omega_B \approx 0.05$), non-baryonic dark matter ($\Omega_{Dark} \approx 0.22$) and dark energy…
In this work we review some of the theoretical efforts and experimental evidences related to Dark matter and Dark energy problems in the universe. These dilemmas show us how incomplete our knowledge of gravity is, and how our concepts about…
Recent cosmological observations suggest that nearly seventy per cent of the energy density in the universe is unclustered and has negative pressure. Several conceptual issues related to the modeling of this component (`dark energy'), which…
There is almost universal agreement among cosmologists that most of the matter in the Universe is dark, and there are very good reasons to believe that most of this dark matter must be nonbaryonic. The two leading candidates for this dark…
Gravitational force manifested in its affect on rotational velocity is what indicates the presence of dark matter in individual galaxies. Newtonian mechanics is generally used to derive the relationship between rotational velocity and…
The cosmological concordance model contains two separate constituents which interact only gravitationally with themselves and everything else, the dark matter and the dark energy. In the standard dark energy models, the dark matter makes up…
We point out that current constraints on dark matter imply only that the majority of dark matter is cold and collisionless. A subdominant fraction of dark matter could have much stronger interactions. In particular, it could interact in a…
We demonstrate how the two dominant constituents of the Universe, dark energy and dark matter, could possess a large scattering cross-section without considerably impacting observations. Unlike models involving energy exchange between the…
Dark matter, baryonic matter and dark energy have different properties but contribute comparable energy density to the present Universe. We point out that they may have a common origin. As the dark energy has a scale far lower than all…
It has been revealed using microlensing that a considerable part, possibly more than half, of the dark matter in the halo of our Galaxy consists of objects with a mass spectrum ranging from 0.05 to 0.8 of the solar mass. What is the nature…
In these lectures we first briefly review the main observational facts which imply that most part of matter in the Universe is not visible and some recent intriguing experimental data which would point to a significant contribution to Omega…
Dark matter has been introduced to explain many independent gravitational effects at different astronomical scales, in galaxies, groups of galaxies, clusters, superclusters and even across the full horizon. This review describes the…
The fact that dark matter (DM), thus far, has revealed itself only on scales of galaxies and larger, again thrusts onto astrophysics the opportunity and the responsibility to confront the age old mystery "What is the nature of matter?" By…
We study the formation and properties of dark neutron stars in a scenario where dark matter is made up of (heavy) dark baryons in a sequestered copy of the MSSM. This scenario naturally explains the coincidence of baryonic and dark matter…
A substantial fraction the stellar mass attributed to galaxies is invisible: stars close to the hydrogen burning limit, brown dwarfs, white dwarfs, neutron stars and black holes. These constituents do, however, gravitationally micro-lens…
There is plenty of evidence that most matter in the Universe is dark (non-luminous). Particle physics offers several possible explanations. In this talk I focus on cold dark matter; the most promising candidates are then axions and the…
Dark sector, constituting about 95 percent of the Universe, remains the subject of numerous studies. There are lots of models dealing with the cause of the effects assigned to dark matter and dark energy. This brief review is devoted to the…