论文标题
宇宙弦乐中磁场的演变
Evolution of magnetic fields in cosmic string wakes
论文作者
论文摘要
我们研究宇宙弦中磁场的演变，其电阻率低的等离子体中唤醒。尾流中的初始磁场是在宇宙弦周围颗粒的运动产生的磁场上建模的。血浆的特征是高β值。我们发现了弦之后的多个震动，例如在弦之后发展的结构。我们研究了使用2-D磁流体动力学模拟，研究了减震器的详细结构和冲击中磁场的演变。正如预期的那样，磁场的发展不取决于$β$值。我们的结果表明，而不是在宇宙弦后面形成的单一统一冲击，而是在弦线后面的短时间间隔内形成多个冲击。由于这些签名取决于冲击产生的温度波动，因此多次冲击的存在肯定会影响宇宙弦唤醒的观察性特征。我们还发现，随着冲击的移动，残留的磁场留在后面重新连接并迅速消散。因此，弦周围的磁场非常局部。我们发现磁场重新连接发生在宇宙弦唤醒中。这会导致磁场后区域的磁场减少。
We study the evolution of magnetic fields in cosmic string wakes in a plasma with a low resistivity. The initial magnetic field in the wake is modelled on the magnetic fields that are generated by the motion of particles around cosmic strings. The plasma is characterized by a high beta value. We find multiple shock like structures developing in the wake of the string. We study the detailed structure of the shocks formed and the evolution of the magnetic field in the shock using a 2-D magnetohydrodynamic simulation. As expected, the development of the magnetic field does not depend on the $β$ value. Our results show that instead of a singe uniform shock forming behind the cosmic string we have multiple shocks forming at short time intervals behind the string. The presence of multiple shocks will definitely affect the observational signatures of cosmic string wakes as these signatures depend upon the temperature fluctuations generated by the shock. We also find that as the shock moves away, the residual magnetic field left behind reconnects and dissipates rapidly. The magnetic field around the string is thus very localized. We find that magnetic field reconnections take place in cosmic string wakes. This leads to the decrease of the magnetic field in the post shock region.
