论文标题
比较域壁进化的参数和非参数速度依赖性的单尺度模型
Comparing parametric and non-parametric velocity-dependent one-scale models for domain wall evolution
论文作者
论文摘要
我们在最近提出的无参数速度依赖性的单尺度模型和域壁网络宇宙学演化的标准参数模型之间进行了详细的比较。我们发现后者高估了由于哈勃膨胀而导致的壁运动阻尼，并忽略了壁衰变对网络根平方速度进化的直接影响。我们表明这些效果很重要，但可能会吸收到动量参数的重新定义中。我们还讨论了这些发现对宇宙字符串的含义。我们在宇宙学模型的背景下，使用我们的非参数速度依赖性的单一尺度模型来计算宇宙域壁进化的标准参数模型的能量损失和动量参数，该模型具有cesmic timic $ t $ t $ t $ a \ propto t^λ$ 0 <1 $ 0 <1 <1 <1 <1 <c simer t $ t $ a $ a $ a $ a $ a $ a $ a $ a $的动力的演变，以及我们进一步提供了简单的线性函数，该功能大致近似于$λ$的能量损失和动量参数的依赖性。
We perform a detailed comparison between a recently proposed parameter-free velocity-dependent one-scale model and the standard parametric model for the cosmological evolution of domain wall networks. We find that the latter overestimates the damping of the wall motion due to the Hubble expansion and neglects the direct impact of wall decay on the evolution of the root-mean-square velocity of the network. We show that these effects are significant but may be absorbed into a redefinition of the momentum parameter. We also discuss the implications of these findings for cosmic strings. We compute the energy loss and momentum parameters of the standard parametric model for cosmological domain wall evolution using our non-parametric velocity-dependent one-scale model in the context of cosmological models having a power law evolution of the scale factor $a$ with the cosmic time $t$ ($a \propto t^λ$, $0 < λ< 1$), and compare with the results obtained from numerical field theory simulations. We further provide simple linear functions which roughly approximate the dependence of the energy loss and momentum parameters on $λ$.
