论文标题
严格的二次家族关键轨道的数字
Rigorous numerics for critical orbits in the quadratic family
论文作者
论文摘要
我们开发算法和技术来计算临界点的有限轨道的严格界限,对于参数值的间隔,在一维映射的二次族中$ f_a(x)= a -x^2 $。我们通过构建一个动态定义的分区$ \数学间隔$ω= [1.4,2] $的动态定义分区$ \数学p $来说明我们的方法的有效性,以将近400万个子间隙,对于每个$ n $ n $ and time $ n $ and the Dynamed Interyanties and the Privationals and Dynationals and Antermant of Dynational of的巨大点,几个可能的数量可能会构成几个阶段的数量,可能会有几个阶段的数量。我们还将$ \ Mathcal P $细分为一个家庭$ \ Mathcal p^{+} $,我们称之为随机间隔和一个家庭$ \ Mathcal p^{ - } $,我们称之为常规间隔。我们从数字上证明,每个间隔$ω\ in \ Mathcal p^{+} $都有一个逃生时间,这大致意味着在$ω$中占用所有参数的临界点的某些迭代在相位空间中具有相当大的宽度。这反过来表明,属于$ \ Mathcal p^{+} $中间隔的大多数参数是随机的,并且大多数参数属于$ \ Mathcal p^{ - } $中的间隔是常规的,因此名称。我们证明,$ \ Mathcal p^{+} $中的间隔几乎占$ω$的总量度的90%。该软件和数据可在http://www.pawelpilarczyk.com/quadr/上免费获得,并提供了一个网页以进行计算。这些想法和程序可以很容易地概括为应用于动态系统的其他参数化家族。
We develop algorithms and techniques to compute rigorous bounds for finite pieces of orbits of the critical points, for intervals of parameter values, in the quadratic family of one-dimensional maps $f_a (x) = a - x^2$. We illustrate the effectiveness of our approach by constructing a dynamically defined partition $\mathcal P$ of the parameter interval $Ω=[1.4, 2]$ into almost 4 million subintervals, for each of which we compute to high precision the orbits of the critical points up to some time $N$ and other dynamically relevant quantities, several of which can vary greatly, possibly spanning several orders of magnitude. We also subdivide $\mathcal P$ into a family $\mathcal P^{+}$ of intervals which we call stochastic intervals and a family $\mathcal P^{-}$ of intervals which we call regular intervals. We numerically prove that each interval $ω\in \mathcal P^{+}$ has an escape time, which roughly means that some iterate of the critical point taken over all the parameters in $ω$ has considerable width in the phase space. This suggests, in turn, that most parameters belonging to the intervals in $\mathcal P^{+}$ are stochastic and most parameters belonging to the intervals in $\mathcal P^{-}$ are regular, thus the names. We prove that the intervals in $\mathcal P^{+}$ occupy almost 90% of the total measure of $Ω$. The software and the data is freely available at http://www.pawelpilarczyk.com/quadr/, and a web page is provided for carrying out the calculations. The ideas and procedures can be easily generalized to apply to other parametrized families of dynamical systems.