Emergence of Fluctuations from a Tachyonic Big Bang

Abstract

It has recently been speculated that the end state of a collapsing universe is a tachyonic big crunch. The time reversal of this process would be the emergence of an expanding universe from a tachyonic big bang. In this framework, we study the emergence of cosmological fluctuations. In particular, we compare the amplitude of the perturbations at tne end of the tachyon phase with what would be obtained assuming the usual vacuum initial conditions. We find that cosmological fluctuations emerge in a thermal state. We comment on the relation to the trans-Planckian problem of inflationary cosmology.

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References in corpus (5)

• String Gas Cosmology and Structure Formation
• Open String Creation by S-Branes
• Dimension-changing exact solutions of string theory
• Towards A Nonsingular Tachyonic Big Crunch
• The Nothing at the Beginning of the Universe Made Precise

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• Tachyon - Dilaton driven Inflation as an alpha' - non-perturbative solution in First Quantized String Cosmology