Institute of Theoretical Astrophysics, University of Oslo, N-0315 Oslo, Norway.
Phys Rev Lett. 2013 Apr 19;110(16):161101. doi: 10.1103/PhysRevLett.110.161101. Epub 2013 Apr 15.
Several extensions of general relativity and high energy physics include scalar fields as extra degrees of freedom. In the search for predictions in the nonlinear regime of cosmological evolution, the community makes use of numerical simulations in which the quasistatic limit is assumed when solving the equation of motion of the scalar field. In this Letter, we propose a method to solve the full equations of motion for scalar degrees of freedom coupled to matter. We run cosmological simulations which track the full time and space evolution of the scalar field, and find striking differences with respect to the commonly used quasistatic approximation. This novel procedure reveals new physical properties of the scalar field and uncovers concealed astrophysical phenomena which were hidden in the old approach.
几种广义相对论和高能物理的扩展包括标量场作为额外的自由度。在寻找宇宙学演化的非线性区的预测时，研究人员利用数值模拟，在模拟中，在求解标量场的运动方程时，假设准静态极限。在这封信中，我们提出了一种方法来解决与物质耦合的标量自由度的完整运动方程。我们运行宇宙学模拟，跟踪标量场的完整时间和空间演化，并发现与常用的准静态近似相比有显著差异。这种新的方法揭示了标量场的新物理性质，并揭示了旧方法中隐藏的隐藏的天体物理现象。
