Henry Hervé, Levine Herbert
Center for Theoretical Biological Physics, University of California, San Diego, California 92093-0318, USA.
Phys Rev E Stat Nonlin Soft Matter Phys. 2003 Sep;68(3 Pt 1):031914. doi: 10.1103/PhysRevE.68.031914. Epub 2003 Sep 30.
Motivated by recent experiments on intracellular calcium dynamics, we study the general issue of fluctuation-induced nucleation of waves in excitable media. We utilize a stochastic Fitzhugh-Nagumo model for this study, a spatially extended nonpotential pair of equations driven by thermal (i.e., white) noise. The nucleation rate is determined by finding the most probable escape path via minimization of an action related to the deviation of the fields from their deterministic trajectories. Our results pave the way both for studies of more realistic models of calcium dynamics as well as of nucleation phenomena in other nonequilibrium pattern-forming processes.
受近期关于细胞内钙动力学实验的启发，我们研究了可激发介质中波动诱导波的成核这一普遍问题。我们利用一个随机菲茨休 - 纳古莫模型进行此项研究，该模型是由热（即白）噪声驱动的一对空间扩展的非势方程。通过最小化与场偏离其确定性轨迹相关的作用量来找到最可能的逃逸路径，从而确定成核速率。我们的结果为研究更现实的钙动力学模型以及其他非平衡图案形成过程中的成核现象铺平了道路。
