论文标题
在标量引起的重力波的量规上：考虑的量规固定器
On the Gauge Invariance of Scalar Induced Gravitational Waves: Gauge Fixings Considered
论文作者
论文摘要
能量密度光谱是可观察到的引力波。差异已经出现在标量诱导的不同量规固定的引力波的能量密度光谱中。为了解决差异，我们研究了标量引起的重力波的规格不变性。结果表明，可以通过引入由一阶标量扰动组成的计数项来减去虚拟张量的扰动来获得量规不变的引力波。内核函数唯一地确定标量引起的重力波的能量密度光谱。我们分别在牛顿仪和均匀密度仪表中明确计算规格不变的内核函数。在规格不变的框架中，显示出牛顿量规上的能量密度光谱与均匀密度仪表之间的差异。实际上，其他类型的量规固定措施也可以使用规格不变的方法。
The energy density spectrum is an observable of gravitational waves. Divergence has appeared in the energy density spectra of the scalar induced gravitational waves for different gauge fixings. To resolve the discrepancy, we investigate the gauge invariance of the scalar induced gravitational waves. It is shown that the gauge invariant induced gravitational waves can be obtained by subtracting the fictitious tensor perturbations via introducing the counter term composed of the first order scalar perturbations. The kernel function uniquely determines the energy density spectrum of the scalar induced gravitational waves. We explicitly calculate the gauge invariant kernel functions in the Newtonian gauge and the uniform density gauge, respectively. The discrepancy between the energy density spectra upon the Newtonian gauge and the uniform density gauge is shown to be eliminated in the gauge invariant framework. In fact, the gauge invariant approach is also available to other kinds of gauge fixings.
