相关论文: Dark Matter: Introduction
There is a growing sense of `crisis' in the dark matter community, due to the absence of evidence for the most popular candidates such as weakly interacting massive particles, axions, and sterile neutrinos, despite the enormous effort that…
A cosmology is considered driven by a stress-energy tensor consisting of a perfect fluid, an inhomogeneous pressure term (which we call a ``tachyonic dust'' for reasons which will become apparent) and a cosmological constant. The…
Most of the matter in the universe is invisible. I review the status of dark matter and describe how both the theory of galaxy formation and novel types of experimental searches are revitalizing attempts to find non-baryonic dark matter.
It has been shown beyond reasonable doubt that the majority (about 95%) of the total energy budget of the universe is given by the dark components, namely Dark Matter and Dark Energy. What constitutes these components remains to be…
Astrophysical observations indicate that about 23% of the energy density of the universe is in the form of non-baryonic particles beyond the standard model of particle physics. One exciting and well motivated candidate is the lightest…
Searches for dark matter (DM) constituents are presently mainly focused on axions and WIMPs despite the fact that far higher mass constituents are viable. We discuss and dispute whether axions exist and those arguments for WIMPs which arise…
The present standard model of cosmology states that the known particles carry only a tiny fraction of total mass and energy of the Universe. Rather, unknown dark matter and dark energy are the dominant contributions to the cosmic energy…
In the first section, I will try to convey a sense of the variety of observational inputs that tell us about the existence and the spatial distribution of dark matter in the universe. In the second section, I will briefly review the four…
The nature of the dark matter in the haloes of galaxies is one of the outstanding questions in astrophysics. All stellar candidates, until recently thought to be likely baryonic contributions to the Halo of our Galaxy, are shown to be ruled…
Experimental evidence suggests that we live in a spatially flat, accelerating universe composed of roughly one-third of matter (baryonic + dark) and two-thirds of a negative-pressure dark component, generically called dark energy. The…
One of the most puzzling problems of modern physics is the identification of the nature a non-relativistic matter component present in the universe, contributing to more than 25$\%$ of the total energy budget, known as Dark Matter. Weakly…
The cosmological observations of gravitational lenses, cosmic microwave background, rotation speed of stars in galaxies confirm the existence of about 27% dark matter in the Universe. The nature of these particles is unknown, however, there…
Dark energy in the universe is assumed to be vacuum energy. The energy-momentum of vacuum is described by a scale-dependent cosmological constant. The equations of motion imply for the density of matter (dust) the sum of the usual matter…
Solving the Dark Matter enigma represents one of the key objectives of contemporary physics. Recent astrophysical and cosmological measurements have unambiguously demonstrated that ordinary matter contributes to less than 5 % of the energy…
The quantum model of the homogeneous, isotropic, and spatially closed universe predicts an existence of two types of collective quantum states in the universe. The states of one type characterize a gravitational field, the others describe a…
The presence of dark energy in the Universe is inferred directly from the accelerated expansion of the Universe, and indirectly, from measurements of cosmic microwave background (CMB) anisotropy. Dark energy contributes about 2/3 of the…
Dark matter (comprising a quarter of the Universe) is usually assumed to be due to one and only one weakly interacting particle which is neutral and absolutely stable. We consider the possibility that there are several coexisting…
Two exotic elements have been introduced into the standard cosmological model: non-baryonic dark matter and dark energy. The success in converting a hypothesis into a solid theory depends strongly on whether we are able to solve 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 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…