Cosmological perturbation analysis in a scale invariant model of gravity
Cosmological perturbation analysis in a scale invariant model of gravity
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DOI：
10.1088/0264-9381/28/21/215010
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发表时间：
2011-05
影响因子：
3.5
通讯作者：
P. Jain;P. Karmakar;S. Mitra;S. Panda;Naveen K. Singh
中科院分区：
文献类型：
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作者：
P. Jain;P. Karmakar;S. Mitra;S. Panda;Naveen K. Singh
我们考虑了一个在全局尺度变换下不变的引力模型。它包括一个非最小耦合到重力场的额外实标量场。在这个模型中，所有的量纲参数，如引力常数和宇宙常数等，都是通过求解经典的运动方程来产生的。因此，该解决方案提供了一种打破尺度不变性的机制。在这篇文章中，我们证明了这种解在平坦的FRW背景下对小扰动的稳定性，方法是在解的周围做微扰展开，并求解得到的方程在微扰中是线性的。这证明了这种对称破缺机制的健壮性。
We consider a model for gravity that is invariant under global scale transformations. It includes one extra real scalar field coupled non-minimally to the gravity fields. In this model all the dimensionful parameters such as the gravitational constant and the cosmological constant etc are generated by a solution of the classical equations of motion. Hence, this solution provides a mechanism to break scale invariance. In this paper, we demonstrate the stability of such a solution against small perturbations in a flat FRW background by making a perturbative expansion around this solution and solving the resulting equations linear in the perturbations. This demonstrates the robustness of this symmetry breaking mechanism.