Curvatons in warped throats
Curvatons in warped throats
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DOI：
10.1088/1475-7516/2009/07/032
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发表时间：
2009-05
影响因子：
6.4
通讯作者：
Takeshi Kobayashi;S. Mukohyama
中科院分区：
文献类型：
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作者：
Takeshi Kobayashi;S. Mukohyama
我们提出了一个来自 IIB 型弦理论的曲率模型，该模型在具有近似等距的扭曲喉部上被压缩。考虑将位于喉尖的（反）D3 膜作为原型标准模型膜，我们表明膜在等距方向上的位置可以发挥曲率的作用。基本情况是，膨胀过程中（反）D3 膜在角等距方向上的波动最终转变为原初曲率扰动，随后膜的振荡激发了膜上的其他开弦模式并重新加热宇宙。我们发现在 KS 喉咙的明确情况下，各种参数允许一致的曲线场景。研究还表明，喉尖处的膜振动能够通过曲率或等曲率扰动产生较大的非高斯性。由于这种设置自然出现在扭曲的（多）喉部致密化中，并且受到观测数据的约束，因此该模型可以为致密化场景提供测试。这项工作给出了弦理论的一个明确的例子，提供了用于生成曲率扰动的光场。这种机制使暴胀子不再对扰动负责，从而为暴胀模型开辟了新的可能性。
We present a curvaton model from type IIB string theory compactified on a warped throat with approximate isometries. Considering an (anti-)D3-brane sitting at the throat tip as a prototype standard model brane, we show that the brane's position in the isometry directions can play the role of curvatons. The basic picture is that the fluctuations of the (anti-)D3-brane in the angular isometry directions during inflation eventually turns into the primordial curvature perturbations, and subsequently the brane's oscillation excites other open string modes on the brane and reheat the universe. We find in the explicit case of the KS throat that a wide range of parameters allows a consistent curvaton scenario. It is also shown that the oscillations of branes at throat tips are capable of producing large non-Gaussianity, either through curvature or isocurvature perturbations. Since such setups naturally arise in warped (multi-)throat compactifications and are constrained by observational data, the model can provide tests for compactification scenarios. This work gives an explicit example of string theory providing light fields for generating curvature perturbations. Such mechanisms free the inflaton from being responsible for the perturbations, thus open up new possibilities for inflation models.