Physical Aging in Oscillatory and Excitable Systems

我们项目的目的是研究经典振荡和可激发系统的物理老化、记忆和返老还童效应。到目前为止，在大量出版物中对自旋系统、自旋玻璃、聚合物玻璃和其他材料中的这种效应进行了研究；它们仍然是挑战失衡动力学的一部分。由于我们所关注的系统在遗传、细胞、神经和生态网络中有着完全不同的应用范围，我们的研究可能会开辟一个新的研究分支。我们猜想在振荡和可激发系统中发现类似的老化过程的原因是基于我们之前关于挫折感、无序和噪声的影响、这些系统中出现的多稳定性、慢弛豫和粗粒图案的结果；所有这些都是老化自旋系统的典型成分，特别是在自旋玻璃中。因此，我们将主要在有或没有无序和沮丧的振荡器和可兴奋单元的原型系统中寻找衰老的表现。随着老化和动力学标度行为的识别，寻找普适类，特别是与自旋玻璃和其他材料的已知动力学标度行为的比较。最初，在自旋系统和不平衡的材料中发现普遍的标度定律是令人惊讶的；现在，将这些普适类扩展到包含具有非常不同微观动力学的系统，将同样令人惊讶，就像发现新的普适类一样。目前，是否存在以及如果存在的话，在各种现象背后存在哪些共同的潜在微观机制是一个悬而未决的问题：自旋系统和材料中的物理老化，生物系统简单模型中的物理老化，这是本项目的重点，以及复杂的多层次生物系统活着。由于设想的振荡和可激发系统在微观上与以前考虑的系统非常不同，我们假设这个项目可以帮助揭示这些机制。

The aim of our project is to investigate physical aging, memory and rejuvenation effects in classical oscillatory and excitable systems. So far such effects were studied in spin systems, spin glasses, polymer glasses and other materials in a large number of publications; they are still topical as a part of challenging out-of-equilibrium dynamics. Since the systems of our focus have a completely different range of applications in genetic, cellular, neural and ecological networks, our studies may open a new branch of research. The reason for our conjecture to find analogous aging processes in oscillatory and excitable systems is based on our previous results on the impact of frustration, disorder and noise, the occurrence of multistability, of slow relaxations and coarse-grained patterns in these systems; all these are typical ingredients in aging spin systems, particularly in spin glasses. Therefore we shall search primarily for manifestations of aging in prototypical systems of oscillators and excitable units with and without disorder and frustration. Along with the identification of aging and dynamical scaling behavior goes the search for universality classes, in particular the comparison with known dynamical scaling behavior from spin glasses and other materials. Originally the very fact to find universal scaling laws in spin systems and materials out-of-equilibrium came as a surprise; now an extension of these universality classes towards an inclusion of systems with very different microscopic dynamics would be not less amazing as well as the discovery of new universality classes. Currently it is an open question whether at all, and if so, which common underlying microscopic mechanisms exist behind the various phenomena: physical aging in spin systems and materials, physical aging in simple models of biological systems, which are in the focus of this project, and complex multi-level biological systems alive. Since the envisaged oscillatory and excitable systems are microscopically very distinct from formerly considered systems, we assume that this project can contribute to uncover these mechanisms.