论文标题
仪表不变的二阶重力波
Gauge Invariant Second Order Gravitational Waves
论文作者
论文摘要
我们通过遵循Lie Verivive方法来研究由一阶标量扰动引起的二阶重力波的规格不变性。明确表明，二阶重力波在同步框架中不变。在规格不变的框架中，我们得出了二阶重力波的运动方程，并表明二阶重力波从牛顿牛顿不变的牛顿框架中很好地描述的一阶标量扰动中得出。由于在同步框架中测量了引力波的观察物，因此我们根据规格不变的同步变量来定义二阶重力波的能量密度光谱。这种方式保证没有虚拟张量的扰动。结果表明，二阶重力波的规格不变能密度光谱与牛顿量规中的量规相吻合。
We investigate the gauge invariance of the second order gravitational waves induced by the first order scalar perturbations by following the Lie derivative method. It is shown explicitly that the second order gravitational waves are gauge invariant in the synchronous frame. In the gauge invariant framework, we derive the equation of motion of the second order gravitational waves and show that the second order gravitational waves are sourced from the first order scalar perturbations described well in the gauge invariant Newtonian frame. Since the observables of gravitational waves are measured in the synchronous frame, we define the energy density spectrum of the second order gravitational waves in terms of the gauge invariant synchronous variables. This way guarantees no fictitious tensor perturbations. It is shown that the gauge invariant energy density spectrum of the second order gravitational waves coincides with the one in the Newtonian gauge.
