论文标题
摇摆宇宙字符串的缩放溶液：ii。时变的粗粒量表解决方案
Scaling solutions of wiggly cosmic strings: II. Time-varying coarse-graining scale solutions
论文作者
论文摘要
通过研究其允许的渐近缩放溶液，我们继续探索宇宙字符串速度依赖性的一个尺度模型的摇摆概括。我们扩展了以前的论文[Almeida $ \＆$ Martins，Phys。 Rev. D 104（2021）043524]通过考虑弦摇摆的时变粗粒量表的更全面的情况。因此，网络的演变建模依赖于三种主要机制：哈勃扩展，能量转移机制（例如，循环和摆动的产生）以及摇摆的尺度的选择。我们分析了它们每个人在网络的整体行为中的作用，因此分析了允许的缩放解决方案。在Minkowski空间中，我们发现，随着平均尺度的变化，无法在没有扩展的数值模拟中观察到的线性缩放。对于扩大的宇宙，我们发现，三种广泛的缩放解决方案（随着摇摆不定，达到缩放或增长）仍然存在，但仍存在着不同的影响，但受粗粒尺度的时间演变的影响。 NAMBU-GOTO型解决方案（无摇摆）不受影响，越来越多的Wiggliness解决方案是微不足道的，而对于Wiggliness达到缩放的膨胀速率的解决方案，相对于固定的粗粒尺度，溶液的膨胀速率降低了。最后，我们还表明，包含时变的粗粒量表原则上允许其他缩放解决方案，尽管在数学上有效，但并非物理。总体而言，我们对wiggly速度依赖性一个尺度模型的允许缩放解决方案的景观的映射为模型的详细测试铺平了道路，该模型将通过即将到来的高分辨率现场理论和Nambu-Goto模拟来完成。
We continue our exploration of the wiggly generalisation of the Velocity-Dependent One Scale Model for cosmic strings, through the study of its allowed asymptotic scaling solutions. We extend the work of a previous paper [Almeida $\&$ Martins, Phys. Rev. D 104 (2021) 043524] by considering the more comprehensive case of a time-varying coarse-graining scale for the string wiggles. The modeling of the evolution of the network therefore relies on three main mechanisms: Hubble expansion, energy transfer mechanisms (e.g., the production of loops and wiggles) and the choice of the scale at which wiggles are coarse-grained. We analyse the role of each of them on the overall behaviour of the network, and thus in the allowed scaling solutions. In Minkowski space, we find that linear scaling, previously observed in numerical simulations without expansion, is not possible with a changing averaging scale. For expanding universes, we find that the three broad classes of scaling solutions -- with the wiggliness disappearing, reaching scaling, or growing -- still exist but are differently impacted by the time evolution of the coarse-graining scale. Nambu-Goto type solutions (without wiggles) are unaffected, growing wiggliness solutions are trivially generalized, while for solutions where wiggliness reaches scaling the expansion rate for which the solution exists is decreased with respect to the one for a fixed coarse-graining scale. Finally, we also show that the inclusion of a time-varying coarse-graining scale allows, in principle, for additional scaling solutions which, although mathematically valid, are not physical. Overall, our mapping of the landscape of the allowed scaling solutions of the wiggly Velocity-Dependent One Scale Model paves the way for the detailed testing of the model, to be done by forthcoming high-resolution field theory and Nambu-Goto simulations.
