arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2006.04051math.CAcs.NAmath.NA
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关于分数阶时滞微分方程的初始条件

On initial conditions for fractional delay differential equations

Roberto Garrappa, Eva Kaslik

摘要:

分数阶导数有不同的引入方式:作为分数次积分的左逆,或者通过推广定义整数阶导数的差商极限。虽然这两种方法(在标准平滑假设下)导致等价的算子,但第一种方法不涉及初始点左侧的函数,相反,后者迫使函数假定选定的值。分数阶时滞微分方程出现了新的问题:时滞的存在不仅要求在初始点上,而且要求在整个区间上分配解。由于初始函数的自由选择,分数阶导数所强制的值可能存在一些不一致,并且算子可能不再等价。本文讨论了分数阶时滞微分方程的初值问题,研究了初始条件对解的影响,同时也研究了初始条件对分数阶算子的影响,以及在分数阶导数的记忆中加入或不加入初始函数所得到的解之间的差别。一个家庭的线性方程组的精确解是由拉普拉斯变换,而数值方法用于解决非线性问题,因此,不同的结果显示和评论。

英文摘要:

Derivatives of fractional order are introduced in different ways: as left-inverse of the fractional integral or by generalizing the limit of the difference quotient defining integer-order derivatives. Although the two approaches lead (under standard smoothness assumptions) to equivalent operators, the first one does not involve the function at the left of the initial point where, instead, the latter forces the function to assume selected values. With fractional delay differential equations new problems arise: the presence of the delay imposes to assign the solution not just at the initial point but on an entire interval. Due to the freedom in the choice of the initial function, some inconsistencies with the values forced by the fractional derivative are possible and the operators may no longer be equivalent. In this paper we discuss the initialization of fractional delay differential equations, we investigate the effects of the initial condition not only on the solution but also on the fractional operator as well and we study the difference between solutions obtained by incorporating or not the initial function in the memory of the fractional derivative. The exact solution of a family of linear equations is obtained by the Laplace transform whilst numerical methods are used to solve nonlinear problems; the different results are therefore shown and commented.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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