Celia Escamilla-Rivera, Gerardo Garcia-Jimenez, Oscar Loaiza-Brito, Octavio Obregon. Closed String Tachyon: Inflation and Cosmological Collapse
Submitted on: Aug 25, 2012, 16:09:52
Natural Sciences / Physics / Gravitation Theory (Relativity)
Description: By compactifying a critical bosonic string theory on an internal non-flat space with a constant volume, we study the role played by the closed string tachyon in the cosmology of the effective four-dimensional space-time. The effective tachyon potential consists on a negative constant related to the internal curvature space and a polynomial with only quadratic and quartic terms of the tachyon field. Based on it, we present a solution for the tachyon field and the scale factor, which describes an accelerated universe which expands to a maximum value before collapsing. At early times, the closed string tachyon potential behaves as a cosmological constant driving the Universe to an expansion. The value of the cosmological constant is determined by the curvature of the internal space which also fixes the value of the vacuum energy. As time evolves, inflation is present in our models, and it finishes long before the collapsing. At late times, we show that the collapse of the Universe starts as soon as the tachyon field condensates.
The Library of Congress (USA) reference page : http://lccn.loc.gov/cn2013300046.
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