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 inflationary , radiation dominated and matter dominated eras are investigated in detail. In all three eras, the tachyonic pressure decreases with increasing radius of ...

We propose a model of generations that has exactly three generations. This model has several attractive features: the large mass differences between the generations has a qualitative explanation, there is a simple way to make the u-d mass difference negative but the c-s and t-b mass differences positive, and there is a simple mechanism to produce the CKM quark mixings and their neutrino analogs...

We introduce a simple family of models for representing the dark matter in galaxies. The potential and phase space distribution function are all elementary, while the density is cusped. The models are all hypervirial, that is, the virial theorem holds locally, as well as globally. As an application to dark matter studies, we compute some of the properties of γ-ray sources caused by neutralino s...

Uncompactified KK universes are so intrinsically connected to the otherwise only empirically required “missing” Dark Matter (DM),

We review how our current understanding of the light element synthesis during the Big Bang Nucleosynthesis era may help shed light on the identity of particle dark matter.

Cosmological arguments proving that the universe is dominated by invisible non-baryonic matter are reviewed. Possible physical candidates for dark matter particles are discussed. A particular attention is paid to non-compensated remnants of vacuum energy, to the question of stability of super-heavy relics, cosmological mass bounds for very heavy neutral lepton, and some other more exotic possib...

An unconventional version of supersymmetry leads to the following highly testable predictions: (1) The Higgs boson has an R-parity of -1, so it can only be produced as one member of a pair of superpartners. (2) The only superpartners are scalar bosons, so the neutralino etc. do not exist. (3) The most likely candidate for cold dark matter is therefore a sneutrino. (4) The Higgs and other bosoni...

The neutralino relic density is calculated in the low-energy effective Minimal Supersymmetric extension of Standard Model (effMSSM). The slepton-neutralino, squarkneutralino and neutralino/chargino-neutralino coannihilation channels are taking into account. The comparative study of these coannihilations is performed and demonstrated that all of them give the sizable contributions to the reducti...