论文标题

COSH梯度系统和倾斜

Cosh gradient systems and tilting

论文作者

Peletier, Mark A., Schlichting, André

论文摘要

我们回顾了一类具有双曲线骨类型耗散电位的梯度系统。我们展示了这种耗散电位如何在跳跃过程的大偏差,扩散过程的多尺度极限等中出现。我们展示了COSH的指数性质如何来自大偏差的指数缩放,并暗中出现在多尺度限制中的细胞问题中。 我们深入讨论梯度系统“倾斜”的作用。某些类别的梯度系统是“无倾斜的”,这意味着更改驱动功能不会导致耗散潜力的变化。这种倾斜的独立性将驱动功能与耗散电位分开,保证了清晰的建模解释,并产生了梯度系统收敛的强烈概念。 我们表明,尽管许多梯度系统通常都是倾斜的,但某些COSH型系统却没有。我们还表明,这是不可避免的,通过详细研究Kramers高激活能量极限的经典示例,其中扩散会收敛到跳跃过程,而Wasserstein梯度系统会收敛到COSH型系统。我们展示并解释了限制系统在极限系统中如何丢失的倾斜独立性。在化学工程文献中,可以在化学反应率的经典理论中识别出同样的独立性。 我们说明在离散环境中类似的倾斜度独立。对于一类“两末端”快速子网,我们对倾斜的依赖性进行了完整的表征,这与等效电网的经典理论非常相似。

We review a class of gradient systems with dissipation potentials of hyperbolic-cosine type. We show how such dissipation potentials emerge in large deviations of jump processes, multi-scale limits of diffusion processes, and more. We show how the exponential nature of the cosh derives from the exponential scaling of large deviations and arises implicitly in cell problems in multi-scale limits. We discuss in-depth the role of "tilting" of gradient systems. Certain classes of gradient systems are "tilt-independent", which means that changing the driving functional does not lead to changes of the dissipation potential. Such tilt-independence separates the driving functional from the dissipation potential, guarantees a clear modelling interpretation, and gives rise to strong notions of gradient-system convergence. We show that although in general many gradient systems are tilt-independent, certain cosh-type systems are not. We also show that this is inevitable, by studying in detail the classical example of the Kramers high-activation-energy limit, in which a diffusion converges to a jump process and the Wasserstein gradient system converges to a cosh-type system. We show and explain how the tilt-independence of the pre-limit system is lost in the limit system. This same lack of independence can be recognized in classical theories of chemical reaction rates in the chemical-engineering literature. We illustrate a similar lack of tilt-independence in a discrete setting. For a class of "two-terminal" fast subnetworks, we give a complete characterization of the dependence on the tilting, which strongly resembles the classical theory of equivalent electrical networks.

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