Early cosmology constrained

Quantum Cosmology of Classically Constrained Gravity

In hep-th/0506040 we discussed a classically constrained model of gravity. This theory contains known solutions of General Relativity (GR), and admits solutions that are absent in GR. Here we study cosmological implications of some of these new solutions. We show that a spatially-flat de Sitter universe can be created from “nothing”. This universe has boundaries, and its total energy equals to ...

Early Reionization in Cosmology

Since this is the first contribution to this meeting which is mainly involved in cosmology, I would like to put it into its cosmological perspective: In the standard model of cosmology we assume that the universe is homogeneous and isotropic on large enough scales. This assumption, originally probably made just by reasons of simplicity, leads to a so called Friedmann Lemâıtre universe which exp...

Early Cosmology and Fundamental Physics

Early Universe Cosmology and Supergravity

Like particle physics cosmology also confronts hierarchical scales; e.g. Planck scale Mp = 2.436 × 10 GeV, and big bang nucleosynthesis scale TBBN ∼ 1 MeV, and uncertainties. Unfortunately there is no direct evidence of thermal history of the Universe beyond T ∼ 1 MeV. Though there are indirect evidences which when tied up with particle physics makes a strong case that thermal history could go ...

A Sterile Neutrino Scenario Constrained by Experiments and Cosmology

We discuss a model in which three active and one sterile neutrino account for the solar, the atmospheric and the LSND neutrino anomalies. It is shown that if Nν < 4 then these and other experiments and big bang nucleosynthesis constrain all the mixing angles severely, and allow only the small-angle MSW solution. If these neutrinos are of Majorana type, then negative results of neutrinoless doub...