论文标题
增强不变的超流量流
Boost-invariant superfluid flows
论文作者
论文摘要
我们为相对论超流体的理想流体动力学提供了一些确切的解决方案，并具有几乎符合状态的状态方程。这些溶液具有应力张量，在洛伦兹（Lorentz）沿一个方向提升下不变，并代表了比约克（Bjorken）和古布斯（Gubser）流的超流体概括。我们还研究了对一阶流体动力学流量的校正，认为耗散是由剪切粘度主导的。我们为这些粘性校正提供了一些简单的数值解决方案。最后，当自发损坏的$ \ mathrm {u}（1）$对超流量的对称性仅近似值时，我们将校正的大小估算为产生的流量，从而使相应的Goldstone Boson具有小的非零质量。我们发现，无质量的解决方案仍然可以在足够小的空间速度下提供良好的近似值。
We present some exact solutions to the ideal hydrodynamics of a relativistic superfluid with an almost-conformal equation of state. The solutions have stress tensors which are invariant under Lorentz boosts in one direction, and represent superfluid generalisations of the Bjorken and Gubser flows. We also study corrections to the flows in first-order hydrodynamics, arguing that dissipation is dominated by the shear viscosity. We present some simple numerical solutions for these viscous corrections. Finally, we estimate the size of corrections to the flows arising when the spontaneously broken $\mathrm{U}(1)$ symmetry responsible for superfluidity is only approximate, giving the corresponding Goldstone boson a small non-zero mass. We find that the massless solutions can still provide good approximations at sufficiently small spatial rapidities.
