Inflation driven by the Galileon field.
Inflation driven by the Galileon field.
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DOI：
10.1103/physrevlett.105.231302
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发表时间：
2010-08
影响因子：
8.6
通讯作者：
Tsutomu Kobayashi;Masahide Yamaguchi;J. Yokoyama
中科院分区：
文献类型：
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作者：
Tsutomu Kobayashi;Masahide Yamaguchi;J. Yokoyama
我们提出了一类新的暴胀模型，G 暴胀，它在拉格朗日中具有类似于伽利略的非线性导数相互作用，其形式为 G(φ,(∇φ)(2))□φ ，所得运动方程为二阶。结果表明，即使在精确的德西特背景下也可以产生（几乎）尺度不变的曲率涨落，并且张量与标量之比可以采用比标准膨胀模型中更大的值，从而违反了标准一致性关系。此外，零能量条件的违反可以在没有任何不稳定性的情况下发生。因此，张量模式的光谱指数可以是蓝色的，这使得通过计划中的 LISA 和 DECIGO 等引力波实验以及即将推出的 Planck 和 CMBpol 等 CMB 实验更容易观察暴胀引起的量子引力波。
We propose a new class of inflation model, G inflation, which has a Galileon-like nonlinear derivative interaction of the form G(ϕ,(∇ϕ)(2))□ϕ in the Lagrangian with the resultant equations of motion being of second order. It is shown that (almost) scale-invariant curvature fluctuations can be generated even in the exactly de Sitter background and that the tensor-to-scalar ratio can take a significantly larger value than in the standard inflation models, violating the standard consistency relation. Furthermore, violation of the null energy condition can occur without any instabilities. As a result, the spectral index of tensor modes can be blue, which makes it easier to observe quantum gravitational waves from inflation by the planned gravitational-wave experiments such as LISA and DECIGO as well as by the upcoming CMB experiments such as Planck and CMBpol.