We study numerically the inhomogeneous pre-big-bang inflation in a spherically symmetric space-time. We find that a large initial inhomogeneity suppresses the onset of the pre-big-bang inflation. We also find that even if the pre-big-bang inflationary stage is realized, the initial inhomogeneities are not homogenized. Namely, during the pre-big-bang inflation “hairs”(irregularities) do not fall...

This paper examines the Kalam cosmological argument, as put forward by William Craig. Craig infers the existence of a personal God from the supposedly finite past of the universe. The temporal finiteness of the universe is based upon philosophical arguments for the presumed impossibility of an actual infinity of past events and is confirmed by two lines of scientific evidence. The arguments aga...

We generalize previous work on inhomogeneous pre-big bang cosmology by including the effect of non-trivial moduli and antisymmetric-tensor/axion fields. The general quasi-homogeneous asymptotic solution—as one approaches the big bang singularity from perturbative initial data—is given and its range of validity is discussed, allowing us to give a general quantitative estimate of the amount of in...

The recent search for a stochastic background of gravitational waves with LIGO interferometers has produced a new upper bound on the amplitude of this background in the 100 Hz region. We investigate the implications of the current and future LIGO results on pre-Big-Bang models of the early Universe, determining the exclusion regions in the parameter space of the minimal pre-Big Bang scenario. A...