论文标题
双曲反应扩散系统中的图灵和波浪不稳定性:二阶时间衍生物和交叉扩散项在模式形成中的作用
Turing and wave instabilities in hyperbolic reaction-diffusion systems: The role of second-order time derivatives and cross-diffusion terms on pattern formation
论文作者
论文摘要
双曲反应扩散方程最近引起了人们对各种生物学和化学现象的应用的关注,以及它们在传播速度和新颖的不稳定性方面的独特特征,在经典的两种物种反应 - 扩散系统中不存在。我们探讨了这种系统的扩散不稳定性和最终模式形成的开始。从对问题的相当普遍的表述开始,我们获得了此类系统中图灵和波浪不稳定性的必要条件,从而对这些扩散不稳定性的出现进行分类。我们发现,附加的时间术语不会强烈修改形成允许它们的形成或参数的图灵模式,而只会改变其存在区域。这与其他空间衍生物的情况相反,在这种情况下,过去的工作表明,所产生的图案结构对二阶交叉扩散和一阶对流很敏感。我们还表明,对于波浪不稳定性下时空模式的出现是必要的。我们发现,对于那些导致固定图灵模式的参数相互排斥的参数存在此类波浪不稳定性。这意味着在激活因素比抑制剂更快扩散的情况下,可能会发生波浪不稳定性,从而导致在反应 - 扩散系统中的空间对称性破坏途径,而反应扩散系统与研究经过良好的图灵案不同。
Hyperbolic reaction-diffusion equations have recently attracted attention both for their application to a variety of biological and chemical phenomena, and for their distinct features in terms of propagation speed and novel instabilities not present in classical two-species reaction-diffusion systems. We explore the onset of diffusive instabilities and resulting pattern formation for such systems. Starting with a rather general formulation of the problem, we obtain necessary and sufficient conditions for the Turing and wave instabilities in such systems, thereby classifying parameter spaces for which these diffusive instabilities occur. We find that the additional temporal terms do not strongly modify the Turing patterns which form or parameters which admit them, but only their regions of existence. This is in contrast to the case of additional space derivatives, where past work has shown that resulting patterned structures are sensitive to second-order cross-diffusion and first-order advection. We also show that additional temporal terms are necessary for the emergence of spatiotemporal patterns under the wave instability. We find that such wave instabilities exist for parameters which are mutually exclusive to those parameters leading to stationary Turing patterns. This implies that wave instabilities may occur in cases where the activator diffuses faster than the inhibitor, leading to routes to spatial symmetry breaking in reaction-diffusion systems which are distinct from the well studied Turing case.