论文标题
随机分形和Noether定理
Stochastic Fractal and Noether's Theorem
论文作者
论文摘要
我们考虑二进制碎片问题,在任何分手事件中,其中一个女儿细分市场以$ p $ $ p $而生存,或者以$ 1 \! - \!p $消失。它描述了随着时间的流逝而演变的随机二元cantor套件,并最终变成了分形。我们通过分析方法和蒙特卡洛模拟研究了这种现象,用于一般的模型类别,其中片段分解点遵循具有形状参数$α$的对称beta分布,这也决定了片段化速率。对于分形尺寸$ d_f $,我们发现$ d_f $ -th Monges $ m_ {d_f} $是保守数量,独立于$ p $和$α$。我们使用数据崩溃的概念 - 动态缩放对称性的结果 - 证明该系统表现出自相似性。为了将对称性与保守数量联系起来,我们将碎片方程重新解释为欧几里得量子力学系统的连续性方程。令人惊讶的是,与动力学缩放相对应的NOETHE电荷是微不足道的,而$ m_ {d_f} $与纯数学对称性:欧几里得时间中的量子力学相位旋转相关。
We consider the binary fragmentation problem in which, at any breakup event, one of the daughter segments either survives with probability $p$ or disappears with probability $1\!-\!p$. It describes a stochastic dyadic Cantor set that evolves in time, and eventually becomes a fractal. We investigate this phenomenon, through analytical methods and Monte Carlo simulation, for a generic class of models, where segment breakup points follow a symmetric beta distribution with shape parameter $α$, which also determines the fragmentation rate. For a fractal dimension $d_f$, we find that the $d_f$-th moment $M_{d_f}$ is a conserved quantity, independent of $p$ and $α$. We use the idea of data collapse -- a consequence of dynamical scaling symmetry -- to demonstrate that the system exhibits self-similarity. In an attempt to connect the symmetry with the conserved quantity, we reinterpret the fragmentation equation as the continuity equation of a Euclidean quantum-mechanical system. Surprisingly, the Noether charge corresponding to dynamical scaling is trivial, while $M_{d_f}$ relates to a purely mathematical symmetry: quantum-mechanical phase rotation in Euclidean time.