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DBI Inflation in the Tip Region of a Warped Throat

Steven Kecskemeti·John Maiden·Gary Shiu·Bret Underwood
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Abstract

Previous work on DBI inflation, which achieves inflation through the motion of a $D3$ brane as it moves through a warped throat compactification, has focused on the region far from the tip of the throat. Since reheating and other observable effects typically occur near the tip, a more detailed study of this region is required. To investigate these effects we consider a generalized warp throat where the warp factor becomes nearly constant near the tip. We find that it is possible to obtain 60 or more e-folds in the constant region, however large non-gaussianities are typically produced due to the small sound speed of fluctuations. For a particular well-studied throat, the Klebanov-Strassler solution, we find that inflation near the tip may be generic and it is difficult to satisfy current bounds on non-gaussianity, but other throat solutions may evade these difficulties.

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Steven Kecskemeti, John Maiden, Gary Shiu, Bret Underwood. 2006-09-29. DBI Inflation in the Tip Region of a Warped Throat. https://doi.org/10.1088/1126-6708%2F2006%2F09%2F076

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