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arXiv 0904.3468math.PR
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突变结构生灭过程的拟平稳分布

Quasi-stationary distributions for structured birth and death processes with mutations

Pierre Collet, Servet Martinez, Sylvie Méléard, Jaime San Martin

摘要:

研究了具有突变和生态相互作用的生灭连续时间测度值过程的概率演化。个体的特征在于在紧凑的度量空间中取值的(表型)性状。每一个个体都可能死亡或产生新的个体。出生率和死亡率可能取决于整个人口活动的环境。后代可以具有相同的特征,也可以突变成随机分布的特征。我们假设这个种群几乎肯定会灭绝。我们的目标是研究,在这个无限维的框架下,准平稳分布的过程是条件不灭绝。我们首先表明,在这个一般的设置,准平稳分布的存在。这一结果是基于一个抽象定理证明存在的有限特征测度的一些积极的运营商。然后,我们考虑一个人口与常数的出生率和死亡率的每一个个体,并证明存在一个唯一的拟平稳分布的最大指数衰减率。唯一性的证明是基于相对于参考测度的绝对连续性。

英文摘要:

We study the probabilistic evolution of a birth and death continuous time measure-valued process with mutations and ecological interactions. The individuals are characterized by (phenotypic) traits that take values in a compact metric space. Each individual can die or generate a new individual. The birth and death rates may depend on the environment through the action of the whole population. The offspring can have the same trait or can mutate to a randomly distributed trait. We assume that the population will be extinct almost surely. Our goal is the study, in this infinite dimensional framework, of quasi-stationary distributions when the process is conditioned on non-extinction. We firstly show in this general setting, the existence of quasi-stationary distributions. This result is based on an abstract theorem proving the existence of finite eigenmeasures for some positive operators. We then consider a population with constant birth and death rates per individual and prove that there exists a unique quasi-stationary distribution with maximal exponential decay rate. The proof of uniqueness is based on an absolute continuity property with respect to a reference measure.

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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