Hot and heavy dark matter from a weak scale phase transition

A Single Scale Theory for Cold and Hot Dark Matter

We show that a recently proposed extension of the minimal supersymmetric standard model can provide a scenario where both the cold and the hot dark matter of the universe owe their origin to a single scale connected with the breakdown of global B − L symmetry. The susy partner of the majoron and the light Majorana neutrinos are the cold and hot dark matter candidates respectively in this model ...

0 Phase Transition in Hot Pion Matter

The equation of state for the pion gas is analyzed within the third virial approximation. The second virial coefficient is found from the ππ-scattering data, while the third one is considered as a free parameter. The proposed model leads to a first-order phase transition from the pion gas to a more dense phase at the temperature Tpt < 136 MeV. Due to relatively low temperature this phase transi...

The Hot Dark Matter

There is a puzzling contradiction: direct observations favor a low-mass-density universe (0.2 ≤ Ωm ≤ 0.6), but the only model which fits universe structure over more than three orders of magnitude in distance scale has a mix of hot (neutrino) and cold dark matter providing a critical density universe. Models of an open universe (low Ωm) or one adding a cosmological constant (Λ) to provide a cri...

Hot Dark Matter

Weak lensing, dark matter and dark energy

Weak gravitational lensing is rapidly becoming one of the principal probes of dark matter and dark energy in the universe. In this brief review we outline how weak lensing helps determine the structure of dark matter halos, measure the expansion rate of the universe, and distinguish between modified gravity and dark energy explanations for the acceleration of the universe. We also discuss requi...