arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 0912.3000cond-mat.stat-mech
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噪声和平流在吸收态相变中的作用

The role of noise and advection in absorbing state phase transitions

C. Barrett-Freeman, M. R. Evans, D. Marenduzzo, J. Tailleur

摘要:

研究了平流和噪声对定向渗流场论的影响。我们表明,即使是一个非常小的平流速度是足以改变的动力学相变的普适类。当噪声被采取成正比的人口密度的平方根,我们发现一个额外的非平衡'spinodal'线分离的区域,其中指数下降的密度是亚稳的,从另一个,其中它是不稳定的。如果噪声在密度上是线性的,则相图在定量和定性上都发生显著变化,并且旋节线成为真正的相边界。我们简要地讨论了我们的研究结果在河流中的微生物沉积和种群动态的可能应用。

英文摘要:

We study the effect of advection and noise on the field theory for directed percolation (DP). We show that even a very small advective velocity is enough to change the universality class of the dynamic phase transition. When the noise is taken to be proportional to the square root of the population density, we find an additional nonequilibrium 'spinodal' line separating a region where an exponentially decreasing density is metastable, from another one in which it is unstable. If the noise is instead linear in the density, the phase diagram changes dramatically both quantitatively and qualitatively, and the spinodal line becomes a true phase boundary. We briefly discuss possible applications of our results to microbial sedimentation and population dynamics in rivers.

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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