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arXiv 2302.03448cond-mat.stat-mech
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随机环境对动力学粗糙化的影响:耦合静态噪声与Navier-Stokes方程的Kardar-Parisi-Zhang模型

Effect of random environment on kinetic roughening: Kardar-Parisi-Zhang model with a static noise coupled to the Navier-Stokes equation

N. V. Antonov, P. I. Kakin, M. A. Reiter

AI总结:

本文针对随机运动介质中的表面动力学粗糙化问题,用场论重整化群方法研究耦合静态噪声的Kardar-Parisi-Zhang模型与Navier-Stokes方程的相互作用,通过扩展作用泛函实现可重整化,发现五维参数空间中存在含红外吸引段的不动点曲线。

摘要:

随机生长表面的动力学粗糙化可通过含时间无关(“空间淬灭”或“柱状”)随机噪声的Kardar-Parisi-Zhang方程建模。本文采用场论重整化群方法,研究随机运动介质对动力学粗糙化的影响。介质由不可压缩粘性流体的随机微分Navier-Stokes方程描述,方程包含外部搅拌力。研究发现,完整随机问题的作用泛函需要扩展才能具备可重整化性:必须引入一种新的非线性项。此外,为正确耦合标量场与速度场,必须引入一个新的无量纲参数作为标量场协变导数的因子。最终得到的作用泛函包含四个耦合常数以及一个运动学系数的无量纲比值。单圈计算(以ε=4-d为展开的领头阶,d为空间维度)表明,这些参数构成的五维空间中的重整化群方程存在一条不动点曲线,当ε>0时该曲线包含一段红外吸引区段。

英文摘要:

Kinetic roughening of a randomly growing surface can be modelled by the Kardar-Parisi-Zhang equation with a time-independent (``spatially quenched'' or ``columnar'') random noise. In this paper, we use the field-theoretic renormalization group approach to investigate how randomly moving medium affects the kinetic roughening. The medium is described by the stochastic differential Navier-Stokes equation for incompressible viscous fluid with an external stirring force. We find that the action functional for the full stochastic problem should be extended to be renormalizable: a new nonlinearity must be introduced. Moreover, in order to correctly couple the scalar and velocity fields, a new dimensionless parameter must be introduced as a factor in the covariant derivative of the scalar field. The resulting action functional involves four coupling constants and a dimensionless ratio of kinematic coefficients. The one-loop calculation (the leading order of the expansion in $\varepsilon=4-d$ with $d$ being the space dimension) shows that the renormalization group equations in the five-dimensional space of those parameters reveal a curve of fixed points that involves an infrared attractive segment for $\varepsilon>0$.

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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