Beyond The Big Bang

The Hot Big Bang and Beyond ∗

The hot big-bang cosmology provides a reliable accounting of the Universe from about 10 sec after the bang until the present, as well as a robust framework for speculating back to times as early as 10 sec. Cosmology faces a number of important challenges; foremost among them are determining the quantity and composition of matter in the Universe and developing a detailed and coherent picture of ...

From Big Bang to Big Crunch and Beyond

We study a quotient Conformal Field Theory, which describes a 3 + 1 dimensional cosmological spacetime. Part of this spacetime is the Nappi-Witten (NW) universe, which starts at a “big bang” singularity, expands and then contracts to a “big crunch” singularity at a finite time. The gauged WZW model contains a number of copies of the NW spacetime, with each copy connected to the preceeding one a...

Looking back in time beyond the big bang

String theory can (in principle) describe gravity at all curvature scales, and can be applied to cosmology to look back in time beyond the Planck epoch. The duality symmetries of string theory suggest a cosmological picture in which the imprint of a primordial, pre-big bang phase could still be accessible to present observations. The predictive power of such a scenario relies, however, on our a...

Big Bang Nucleosynthesis and Physics Beyond the Standard Model

The Hubble expansion of galaxies, the 2.73 K blackbody radiation background and the cosmic abundances of the light elements argue for a hot, dense origin of the universe — the standard Big Bang cosmology — and enable its evolution to be traced back fairly reliably to the nucleosynthesis era when the temperature was of O(1) MeV corresponding to an expansion age of O(1) sec. All particles, known ...

The Big Bang is bang on.