论文标题
随机健身海景的种群灭绝
Population Extinction on a Random Fitness Seascape
论文作者
论文摘要
人口增长和灭绝模型是一个越来越流行的研究主题。但是，尚未充分探索随机性和噪声在塑造分布和结果中的后果。在这里，我们考虑一个分布式人群在每个位置具有逻辑增长，但要遵守“海景”噪声，其中人口的健身随机随机变化，{\ iT位置和时间}。尽管它很简单，但该模型实际上还是在均值视野的透视图中融合了定向渗透的变体和随机介质中的定向聚合物。人口的概率分布可以自信地计算；灭绝转变显示出具有新颖的临界行为，其指数取决于迁移和噪声幅度的强度之比。将结果比较并与由于繁殖随机变化而导致的人口噪声更常规的选择形成鲜明对比。
Models of population growth and extinction are an increasingly popular subject of study. However, consequences of stochasticity and noise in shaping distributions and outcomes are not sufficiently explored. Here we consider a distributed population with logistic growth at each location, subject to "seascape" noise, wherein the population's fitness randomly varies with {\it location and time}. Despite its simplicity, the model actually incorporates variants of directed percolation, and directed polymers in random media, within a mean-field perspective. Probability distributions of the population can be computed self-consistently; and the extinction transition is shown to exhibit novel critical behavior with exponents dependent on the ratio of the strengths of migration and noise amplitudes. The results are compared and contrasted with the more conventional choice of demographic noise due to stochastic changes in reproduction.
