大质量重力与构造形成
Massive gravity and structure formation
摘要：
研究了洛伦兹破坏的大质量引力模型中宇宙学扰动的增长。该模型中的弗里德曼方程由于洛伦兹破坏凝聚体而获得非常规项，其具有状态方程w = -1 /（3 γ），其中γ是取值在[0，1/3]范围之外的自由参数。除了标准贡献外，弗里德曼背景以上的扰动包含一个与空间坐标的任意函数θ（x）成比例的额外部分。这个函数表现为一个积分常数，对应于一个非传播的标量模式，然而，它可能会成为动态的帐户的高阶导数校正。对于-1 < gamma < 0和gamma = 1，“扰动”比标准扰动增长得慢，因此模型与观测相容。在其他γ值下，该模型在实验上是否可接受取决于辐射主导时期开始时函数theta（x）的值。
英文摘要：
We study the growth of cosmological perturbations in the model of Lorentz-violating massive gravity. The Friedman equation in this model acquires an unconventional term due to the Lorentz-breaking condensates which has the equation of state w = -1 / (3 gamma) with gamma being a free parameter taking values outside of the range [0,1/3]. Apart from the standard contributions, the perturbations above the Friedmann background contain an extra piece which is proportional to an arbitrary function theta(x) of the space coordinates. This function appears as an integration constant and corresponds to a non-propagating scalar mode which may, however, become dynamical with the account of the higher-derivative corrections. For -1 < gamma < 0 and gamma = 1 the ``anomalous'' perturbations grow slower than the standard ones and thus the model is compatible with observations. Whether the model is experimentally acceptable at other values of γdepends on the value of the function theta(x) at the beginning of the radiation-dominated epoch.
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