Related papers: Dark Matter and Cold Fractal Clouds
Based on dynamical constraints about the Hubble sequence evolution, observational data and a number of "conspiracies", we propose that the dark matter around spiral galaxies is in the form of cold gas, essentially in molecular form and…
Observations of density profiles of galaxies and clusters constrain the properties of dark matter. Formation of stable halos by collisional fluids with very low mass particles appears as the most probable interpretation, while halos formed…
The bulk of the molecular gas in spiral galaxies is under the form of cold H2, that does not radiate and is only suspected through tracer molecules, such as CO. All tracers are biased, and in particular H2 could be highly underestimated in…
Over the past decade, a consensus picture has emerged in which roughly a quarter of the universe consists of dark matter. The observational evidence for the existence of dark matter is reviewed: rotation curves of galaxies, weak lensing…
The conjecture that dark matter in galaxies is mostly cold fractal gas is developed in the more general context of the thermodynamics of the ideal isothermal gas subject to gravitational instability. This simple gas model already contains…
The nature of the dark matter in the halo of our Galaxy is still largely unknown. The microlensing events found so far towards the Large Magellanic Cloud suggest that at most about 20% of the halo dark matter is in the form of MACHOs…
Dark matter is one of the pillars of the current standard model of structure formation: it is assumed to constitute most of the matter in the Universe. However, it can so far only be probed indirectly through its gravitational effects, and…
We review the most recent evidence for the amazing properties of the density distribution of dark matter around spiral galaxies. Their rotation curves, coadded according to the galaxy luminosity, conform to an universal profile which can be…
The Cold Dark Matter theory of gravitationally-driven hierarchical structure formation has earned its status as a paradigm by explaining the distribution of matter over large spans of cosmic distance and time. However, its central tenet,…
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…
Recent observations have revealed the structural properties of the dark and luminous mass distribution in spirals. These results led to the vision of a new and amazing scenario. The investigation of single and coadded objects has shown that…
In the past years a wealth of observations has unraveled the structural properties of dark and luminous mass distribution in galaxies, a benchmark for understanding dark matter and the process of galaxy formation. The study of the…
Several observational lines of evidence imply that a fraction of the dark matter in the Galaxy may be comprised of small cold clouds of molecular hydrogen. Such objects are difficult to detect because of their small size and low…
Gas cloud models taking into account the recently disclosed fractal structure of cold gas are set up, showing that large errors in the classical gas mass determination based on smooth cloud models can easily follow if the gas is in reality…
More than 90% of matter in the Universe could be composed of heavy particles, which were non-relativistic, or 'cold', when they froze-out from the primordial soup. I will review current searches for these hypothetical particles, both via…
The hypothesis that cold dark matter consists of primordial superheavy particles, the decay of short lifetime component of which led to the observable mass of matter while long living component survived up to modern times manifesting its…
It is now, generally, believed that the presence of some form of dark matter is essential to explain the flat rotation curves of galaxies, and anomalous large velocities of galaxies in the clusters and superclusters. This dark matter turns…
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…
An overview is presented of the main properties of dark matter haloes, as we know them from observations, essentially from rotation curves around spiral and dwarf galaxies. Detailed rotation curves are now known for more than a thousand…
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…