论文标题
在无参数速度依赖性的单尺度模型中，宇宙域壁演化的分析缩放溶液
Analytical scaling solutions for the evolution of cosmic domain walls in a parameter-free velocity-dependent one-scale model
论文作者
论文摘要
我们得出了特征长度$ l $的线性缩放演变的分析近似值以及弗里德曼·罗马·罗伯森 - 罗伯逊 - 罗伯逊 - 沃克森 - 步行者的标准无摩擦域壁网络的根平方速度$σ_v$，具有cosmic time $ t $ t $ prop $ popto $ popto t^$ popto t^^a $ popto t^。这种近似是使用最近提出的无参数速度依赖的域壁尺度模型获得的，可以很好地重现$λ$接近Unity的模型预测，并在$λ\ to 1^ - $ limit中精确地重现。我们使用此近似值，结合$λ= 0 $的确切结果，以获取适合模型预测，适用于$λ\在[0，1 [$ [$）的最大误差$ 1 \％\％$。这种拟合也与现场理论数值模拟的结果非常吻合，特别是[0.9，1 [$。最后，我们明确地表明，原始速度依赖性的单尺度模型的现象学能量损失参数在$λ\至1^ - $限制中消失，并讨论了该结果的含义。
We derive an analytical approximation for the linear scaling evolution of the characteristic length $L$ and the root-mean-squared velocity $σ_v$ of standard frictionless domain wall networks in Friedmann-Lemaître-Robertson-Walker universes with a power law evolution of the scale factor $a$ with the cosmic time $t$ ($a \propto t^λ$). This approximation, obtained using a recently proposed parameter-free velocity-dependent one-scale model for domain walls, reproduces well the model predictions for $λ$ close to unity, becoming exact in the $λ\to 1^-$ limit. We use this approximation, in combination with the exact results found for $λ=0$, to obtain a fit to the model predictions valid for $λ\in [0, 1[$ with a maximum error of the order of $1 \%$. This fit is also in good agreement with the results of field theory numerical simulations, specially for $λ\in [0.9, 1[$. Finally, we explicitly show that the phenomenological energy-loss parameter of the original velocity-dependent one-scale model for domain walls vanishes in the $λ\to 1^-$ limit and discuss the implications of this result.
