Attractor Solutions in Tachyacoustic Cosmology
Attractor Solutions in Tachyacoustic Cosmology
复制标题
速声宇宙学中的吸引子解决方案
DOI：
10.1103/physrevd.86.083502
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发表时间：
2012
影响因子：
5
通讯作者：
W. Kinney
中科院分区：
文献类型：
--
作者：
D. Bessada;W. Kinney
我们研究了“速声”宇宙模型的动力学稳定性，在该模型中，原始扰动是由在减速膨胀期间收缩的声视界产生的。这样的模型代表了暴胀宇宙学的一个潜在替代方案，但是速声解的相空间行为之前还没有被研究过。我们数值计算了两个非正则拉格朗日量，一个类cuscuson的拉格朗日量和一个狄拉克-玻生-因菲尔德的拉格朗日量，它们产生了一个尺度不变的扰动谱。我们证明了两种情况下的幂律背景解都是动态吸引子。
We study the dynamical stability of "tachyacoustic" cosmological models, in which primordial perturbations are generated by a shrinking sound horizon during a period of decelerating expansion. Such models represent a potential alternative to inflationary cosmology, but the phase-space behavior of tachyacoustic solutions has not previously been investigated. We numerically evaluate the dynamics of two non-canonical Lagrangians, a cuscuton-like Lagrangian and a Dirac-Born-Infeld Lagrangian, which generate a scale-invariant spectrum of perturbations. We show that the power-law background solutions in both cases are dynamical attractors.