论文标题
随机流体力学和水力学：相似性和差异
Stochastic hydrodynamics and hydro-kinetics: Similarities and differences
论文作者
论文摘要
水力运动形式主义已被用作求解与嘈杂流体动力学相对的随机微分方程（SDE）的补充方法。水力运动形式主义由一组确定性的弛豫类型方程组成，该方程跟踪随机流体动力学数量的2点相关函数的演变。因此，它们比SDE更容易解决，而SDE在计算上是密集的，需要处理任意较大的梯度。这项工作比较了在比约克水体动力学模型中保守电荷波动的传播和扩散的两种方法。对于白噪声，两种方法都同意。对于因果关系的彩色catteneo噪声，这两个接近差异。这是因为白噪声仅诱导两点相关性，而catteneo噪声也会引起高阶相关性。这种差异是从因果噪声引起的高阶相关性的因果进化和影响的影响中量化的。
The hydro-kinetic formalism has been used as a complementary approach to solving the Stochastic Differential Equations (SDE) corresponding to noisy hydrodynamics. The hydro-kinetic formalism consists of a deterministic set of relaxation type equations that tracks the evolution of 2-point correlation functions of stochastic hydrodynamic quantities. Hence they are comparatively easier to solve than the SDEs, which are computationally intensive and need to deal with arbitrarily large gradients. This work compares the two approaches for the propagation and diffusion of conserved charge fluctuations in the Bjorken hydrodynamic model. For white noise, the two approaches agree. For colored Catteneo noise, which is causal, the two approaches diverge. This is because white noise only induces two-point correlations, while Catteneo noise also induces higher-order correlations. This difference is quantified from the effects of causal evolution and influence from higher-order correlations induced by the Catteneo noise.
