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arXiv 2009.06320nucl-th
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弛豫时间依赖于动量的相对论流体力学

Relativistic hydrodynamics with momentum dependent relaxation time

Sukanya Mitra

摘要:

在相对论输运方程中引入动量相关弛豫时间,导出了二阶相对论流体力学理论。为了做到这一点,已经采用梯度展开方法的迭代技术,即粒子分布函数的Chapman-Enskog(CE)展开。这项工作的主要发现是,(i)碰撞项中的动量依赖弛豫时间导致热力学变量的扩展Landau匹配条件,(ii)Boltzmann方程数值解的结果位于两个流行的极端极限之间:线性和二次幂的相关性,表明弛豫时间中的动量依赖性的分数幂是适当的,(ii)在迭代梯度展开法(如CE)和众所周知的矩方法(如Grad的14-矩方法)之间建立了等价性。

英文摘要:

A second order relativistic hydrodynamic theory has been derived using momentum dependent relaxation time in the relativistic transport equation. In order to do that, an iterative technique of gradient expansion approach, namely Chapman-Enskog (CE) expansion of the particle distribution function has been employed. The key findings of this work are, (i) momentum dependent relaxation time in collision term results in an extended Landau matching condition for the thermodynamic variables, (ii) the result from numerical solution of Boltzmann equation lies somewhere in between the two popular extreme limits : linear and quadratic ansatz, indicating a fractional power of momentum dependence in relaxation time to be appropriate, (ii) an equivalence has been established between the iterative gradient expansion method like CE and the well known moment approach like Grad's 14-moment method.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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