We solve exactly the (linear-order) equations for tensor and scalar perturbations over the homogeneous, isotropic, open pre-big bang model recently discussed by several authors. We find that, in spite of claims to the contrary, vacuum quantum fluctuations, although parametrically amplified, remain negligible throughout the perturbative pre-big bang phase. PACS number(s): 98.80.Cq, 04.30.Db Type...

Using standard big-bang nucleosynthesis and present, high-precision measurements of light element abundances, we place constraints on the self-gravity of radiation pressure in the early universe. The self-gravity of pressure is strictly non-Newtonian, and thus the constraints we set are a direct test of this aspect of general relativity. Subject headings: general relativity; Friedmann equation;...

In pre-big-bang string cosmology one uses a phase of dilaton-driven inflation to stretch an initial (microscopic) spatial patch to the (much larger) size of the big-bang fireball. We show that the dilaton-driven inflationary phase does not naturally iron out the initial classical tensor inhomogeneities unless the initial value of the string coupling is smaller than gin . 10 −35.

Starting from the Janus solution and its gauge theory dual, we obtain the dual gauge theory description of the cosmological solution by the procedure of doubleWick rotation. The coupling is driven either to zero or to infinity at the big-bang and big-crunch singularities, which are shown to be related by the S-duality symmetry. In the dual Yang-Mills theory description, these are non singular a...

Plausible cause and effect of the big bang model are presented without violating conventional laws of physics. The initial cosmological singularity is resolved by introducing the uncertainty principle of quantum theory. We postulate that, preceding the big bang at the end of the gravitational collapse, the total observed mass including all forms of energy of the universe condensed into the prim...

To gain insight in the quantum nature of the big bang, we study the dual field theory description of asymptotically anti-de Sitter solutions of supergravity that have cosmological singularities. The dual theories do not appear to have a stable ground state. One regularization of the theory causes the cosmological singularities in the bulk to turn into giant black holes with scalar hair. We inte...

In two large samples (combined N 1⁄4 31,045), we found a positive relationship between disgust sensitivity and political conservatism. This relationship held when controlling for a number of demographic variables as well as the ‘‘Big Five’’ personality traits. Disgust sensitivity was also associated with more conservative voting in the 2008 U.S. presidential election. In Study 2, we replicated ...

For those of you who are able to stay a little bit longer in these parts, if you are making your way down south to the wine or big timber country, that is the Warren Blackwood education district of which I have the privilege to be the District Director. The Warren Blackwood is a centre for educational excellence in Western Australia. Schools are in recess at the moment, of course, but if you ar...

New Planck scale physics may solve the singularity problems of classical general relativity and may lead to interesting consequences for very early Universe cosmology. Two approaches to these questions are reviewed in this article. The rst is an eeective action approach to including the eeects of Planck scale physics in the basic framework of general relativity. It is shown that eeective action...