Population dynamics in a random environment
Population dynamics in a random environment
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随机环境中的种群动态
DOI：
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发表时间：
2000
期刊：
影响因子：
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通讯作者：
M. Mézard
中科院分区：
文献类型：
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作者：
I. Giardina;J. Bouchaud;M. Mézard
我们研究了随机力场中种群动力学模型中屏障减速和增殖诱导的超扩散之间的竞争。接近临界维d_c=2的单环RG分析预测了亚扩散和超扩散之间的二阶相变，与d=1的数值结果不同，表明出现了一个新的稳定混合不动点。我们引入了扩散辅助势垒穿越的概念，并给出了Flory样的论证来定性地理解在该混合不动点所观察到的扩散行为。
We investigate the competition between barrier slowing down and proliferation induced superdiffusion in a model of population dynamics in a random force field. A one-loop RG analysis close to the critical dimension d_c=2 predicts a second order phase transition between a subdiffusive regime and a superdiffusive regime, at variance with our numerical results in d=1 which suggest that a new stable mixed fixed point appears. We introduce the idea of proliferation assisted barrier crossing and give a Flory like argument to understand qualitatively the observed diffusive behaviour at this mixed fixed point.