在Gandarias [Phys. Lett. A 286(2001)153-160]。在研究了非经典对称性关于变换群的等价性之后,我们对相应势方程的非经典对称性进行了完全的分类。结果,得到了一类新的广义的快扩散方程的势非经典对称。已知的精确非李解的集合补充了类似的。结果表明,所有已知的非李解的快速扩散方程是用尽的那些可以构造在一个规则的方式与上述潜在的非经典对称。发现了快扩散方程的非经典对称类与势非经典对称类之间的联系。
英文摘要:
The fast diffusion equation $u_t=(u^{-1}u_x)_x$ is investigated from the symmetry point of view in development of the paper by Gandarias [Phys. Lett. A 286 (2001) 153-160]. After studying equivalence of nonclassical symmetries with respect to a transformation group, we completely classify the nonclassical symmetries of the corresponding potential equation. As a result, new wide classes of potential nonclassical symmetries of the fast diffusion equation are obtained. The set of known exact non-Lie solutions are supplemented with the similar ones. It is shown that all known non-Lie solutions of the fast diffusion equation are exhausted by ones which can be constructed in a regular way with the above potential nonclassical symmetries. Connection between classes of nonclassical and potential nonclassical symmetries of the fast diffusion equation is found.
Conditional symmetries and exact solutions of a nonlinear three-component reaction-diffusion model
已知三组分反应扩散系统的Q-条件(非经典)对称性[K. Aoki et al Theor. Pop.Biol.50(1)(1996)]首次构建了农民与狩猎采集者之间的交互作用模型。各种各样的Q-条件对称被发现在一个明确的形式,它表明,这些对称是不等价的李对称。应用Q-条件(非经典)对称性算子求反应扩散系统的精确解。的精确解的属性(特别是,他们的渐近行为)进行了鉴定和可能的生物学解释进行了讨论。
Symmetries and exact solutions of a reaction-diffusion system arising in population dynamics
National University of Kyiv-Mohyla Academy(基辅莫希拉国立学院);University of Nottingham(诺丁汉大学);La Trobe University(乐卓博大学);Institute of Mathematics, NAS of Ukraine(乌克兰国家科学院数学研究所)
Reaction-diffusion systems with constant diffusivities: conditional symmetries and form-preserving transformations
研究了一类具有常扩散系数的两组分反应扩散系统的Q-条件对称性(非经典对称性)。利用最近引入的第一类Q-条件对称的概念(R。Cherniha J. Phys. A:Math. Theor.,2010.第43卷,405207),一个详尽的列表反应扩散系统承认这样的对称性。构造了这类系统的保形变换,并证明了该列表只包含非等价系统。所得到的对称性允许减少研究中的反应扩散系统的二维常微分方程系统,并找到精确的解决方案。作为一个非平凡的例子,我们构造了两个非线性反应扩散系统的多参数精确解族。一个可能的解释,以生物学为动机的模型。