相关论文: Scalar field "mini--MACHOs": a new explanation for…
The failure to find evidence for elementary particles that could serve as the constituents of dark matter brings to mind suggestions that dark matter might consist of massive compact objects (MACHOs). In particular, it has recently been…
We propose a novel class of compact dark matter objects in theories where the dark matter consists of multiple sectors. We call these objects $N$-MACHOs. In such theories neither the existence of dark matter species nor their extremely weak…
The nature of the dark matter that binds galaxies remains an open question. The favored candidate has been so far the neutralino. This massive species with evanescent interactions is now in difficulty. It would actually collapse in dense…
To reveal the galactic dark matter in the form of MACHOs ("Massive Astrophysical Compact Halo Objects"), the POINT-AGAPE collaboration is carrying out a search for gravitational microlensing towards M31. A clear microlensing signal is…
The observations of microlensing events in the Large Magellanic Cloud suggest that a sizable fraction ($\sim$ 50%) of the galactic halo is in the form of MACHOs (Massive Astrophysical Compact Halo Objects) with an average mass $\sim 0.27…
The MACHO project has been monitoring about ten million stars in the Large Magellanic Cloud in the search for gravitational microlensing events caused by massive compact halo objects (Machos) in the halo of the Milky Way. In our standard…
Dark matter could take the form of dark massive compact halo objects (dMACHOs); i.e., composite objects that are made up of dark-sector elementary particles, that could have a macroscopic mass from the Planck scale to above the solar mass…
We propose the existence of ultracompact minihalos as a new type of massive compact halo object (MACHO) and suggest an observational test to discover them. These new MACHOs are a powerful probe into the nature of dark matter and physics in…
We report on a search for long duration microlensing events towards the Large Magellanic Cloud. We find none, and therefore put limits on the contribution of high mass objects to the Galactic dark matter. At 95% confidence level we exclude…
MAssive Compact Halo Objects such as brown dwarfs, Jupiters, and black holes are prime candidates to comprise the dark halo of our galaxy. Paczynski noted that objects (dubbed MACHOs) with masses in the range $10^{-6}M_\odot < M \simlt 100…
The dark matter in Galactic halos, or some fraction of it, may be in the form of dark clusters which consist of small mass objects. Carr & Lacey (1987) have derived the permissible properties of such systems, and proposed the existence of…
The nature of the Massive Compact Halo objects seen in microlensing experiments and interpreted as dark matter in the Halo of our Galaxy remains a mystery. Arguments are presented that these events are probably not ordinary stellar or…
Several observations suggest the existence of super-massive black holes (SMBH) at the centers of giant galaxies. However the mechanism under which these objects form remains non completely understood. In this work we review an alternative…
Recent observations of microlensing events in the Large Magellanic Cloud by the MACHO and EROS collaborations suggest that an important fraction of the galactic halo is in form of Massive Astrophysical Compact Halo Objects (MACHOs) with…
We consider the hypothesis that galactic dark matter is composed of ultra-light scalar particles and use internal properties of dwarf spheroidal galaxies to establish a preferred range for the mass m of these bosonic particles. We…
We present the basics of microlensing and give an overview of the results obtained so far. We also describe a scenario in which dark clusters of MACHOs (Massive Astrophysical Compact Halo Objects) and cold molecular clouds (mainly of $H_2$)…
The status of the microlensing search for galactic dark matter in the form of massive astronomical compact halo objects (machos) is reviewed. Unresolved issues are discussed, as well as possible ways to solve these.
The observations of microlensing events in the Large Magellanic Cloud suggest that a sizable fraction (\sim 50%) of the galactic halo is in the form of MACHOs (Massive Astrophysical Compact Halo Objects) with an average mass $\sim 0.27…
Recent high-quality observations of dwarf and low surface brightness (LSB) galaxies have shown that their dark matter (DM) halos prefer flat central density profiles. On the other hand the standard cold dark matter model simulations predict…
By means of extensive galactic modeling we study the implications of the more than eighty microlensing events that have now been observed for the composition of the dark halo of the Galaxy, as well as for other properties of the Galaxy. We…