arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2102.03306math.STmath.CAstat.MEstat.TH
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微分方程、样条和高斯过程

Differential equations, splines and Gaussian processes

Lars Lau Raket

摘要:

我们探讨格林函数的某些微分方程,协方差函数的高斯过程,和光滑样条问题之间的联系。传统上,光滑样条问题被认为是在再生核希尔伯特空间的设置,但在这里,我们提出了一个更直接的方法。利用这种方法,在再生核希尔伯特空间设置中隐含的一些选择脱颖而出,一个例子是边界条件的选择和更精细的形状限制。本文首先探讨了拉普拉斯算子和泊松方程,并在各种边界条件和约束下研究了相应的格林函数。在一系列的例子中推导出显式的函数形式。这些例子包括几种新形式的格林函数,据作者所知,以前没有提出过。接下来,我们提出了一个光滑样条问题,我们惩罚的集成平方导数的功能进行估计。然后,我们将展示如何使用拉普拉斯算子的格林函数来显式计算解决方案。在本文的最后一部分,我们探讨高斯过程和微分方程之间的连接,并显示如何拉普拉斯算子是相关的布朗过程,以及如何出现的过程,由于边界条件和形状的限制,可以被视为条件高斯过程。Laplace算子的格林函数与布朗过程的协方差函数之间的联系使我们能够引入几个新的具有特定行为的布朗过程。最后,我们考虑高斯过程先验和光滑样条之间的联系。

英文摘要:

We explore the connections between Green's functions for certain differential equations, covariance functions for Gaussian processes, and the smoothing splines problem. Conventionally, the smoothing spline problem is considered in a setting of reproducing kernel Hilbert spaces, but here we present a more direct approach. With this approach, some choices that are implicit in the reproducing kernel Hilbert space setting stand out, one example being choice of boundary conditions and more elaborate shape restrictions. The paper first explores the Laplace operator and the Poisson equation and studies the corresponding Green's functions under various boundary conditions and constraints. Explicit functional forms are derived in a range of examples. These examples include several novel forms of the Green's function that, to the author's knowledge, have not previously been presented. Next we present a smoothing spline problem where we penalize the integrated squared derivative of the function to be estimated. We then show how the solution can be explicitly computed using the Green's function for the Laplace operator. In the last part of the paper, we explore the connection between Gaussian processes and differential equations, and show how the Laplace operator is related to Brownian processes and how processes that arise due to boundary conditions and shape constraints can be viewed as conditional Gaussian processes. The presented connection between Green's functions for the Laplace operator and covariance functions for Brownian processes allows us to introduce several new novel Brownian processes with specific behaviors. Finally, we consider the connection between Gaussian process priors and smoothing splines.

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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