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arXiv 1107.0884cond-mat.stat-mechphysics.atom-ph
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具有对数势的Fokker-Planck方程解

Solution of the Fokker-Planck equation with a logarithmic potential

A. Dechant, E. Lutz, E. Barkai, D. A. Kessler

摘要:

本文利用Fokker-Planck方程研究了大$|x|$的一维引力势中粒子的扩散。本征函数展开表明,玻尔兹曼平衡密度并不能完全描述这个问题的长时间限制。相反,这个极限的特征在于一个无限的协变密度。这种不可归一化的密度产生粒子的均方位移,其对于一定范围的参数表现出异常扩散。在具有非对称初始条件的对称势中,平均位置的衰减非常缓慢。这个问题在热环境之外也有应用,如在光学糖蜜中原子动量的扩散。

英文摘要:

We investigate the diffusion of particles in an attractive one-dimensional potential that grows logarithmically for large $|x|$ using the Fokker-Planck equation. An eigenfunction expansion shows that the Boltzmann equilibrium density does not fully describe the long time limit of this problem. Instead this limit is characterized by an infinite covariant density. This non-normalizable density yields the mean square displacement of the particles, which for a certain range of parameters exhibits anomalous diffusion. In a symmetric potential with an asymmetric initial condition, the average position decays anomalously slowly. This problem also has applications outside the thermal context, as in the diffusion of the momenta of atoms in optical molasses.

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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