Instituto de Física, Universidad Nacional Autónoma de México, Distrito Federal 04510, Mexico and Centro de Ciencias de la Complejidad, Universidad Nacional Autónoma de México, Distrito Federal 04510, Mexico.
Instituto de Física, Universidad Nacional Autónoma de México, Distrito Federal 04510, Mexico.
Phys Rev Lett. 2014 Jun 20;112(24):240601. doi: 10.1103/PhysRevLett.112.240601. Epub 2014 Jun 18.
Strongly non-Markovian random walks offer a promising modeling framework for understanding animal and human mobility, yet, few analytical results are available for these processes. Here we solve exactly a model with long range memory where a random walker intermittently revisits previously visited sites according to a reinforced rule. The emergence of frequently visited locations generates very slow diffusion, logarithmic in time, whereas the walker probability density tends to a Gaussian. This scaling form does not emerge from the central limit theorem but from an unusual balance between random and long-range memory steps. In single trajectories, occupation patterns are heterogeneous and have a scale-free structure. The model exhibits good agreement with data of free-ranging capuchin monkeys.
强非马尔可夫随机游走为理解动物和人类的移动性提供了一个很有前途的建模框架,但对于这些过程,可用的分析结果却很少。在这里,我们精确求解了一个具有长程记忆的模型,其中随机游走者根据强化规则间歇性地访问先前访问过的地点。频繁访问的地点的出现产生了非常缓慢的扩散,时间上是对数的,而游走者的概率密度则趋于高斯分布。这种标度形式不是来自中心极限定理,而是来自随机和长程记忆步骤之间的不寻常平衡。在单个轨迹中,占据模式是异构的,具有无标度结构。该模型与自由放养的卷尾猴的数据吻合得很好。