A formula for Hermite multivariate interpolation problem and partial fraction decomposition
Hakop Hakopian
TL;DR
The paper develops a new formula for Hermite multivariate interpolation based on Chung-Yao hyperplane intersections, linking high-dimensional interpolation to univariate polynomial Taylor data. It defines a Taylor-based interpolation representation $p_f(x)=\sum_{k=1}^s\phi_k(x)\mathcal{T}_{f/\phi_k, x^{(k)}, m_k-1}(x)$ using $\phi=\prod L_k$ and $\phi_i$, enabling explicit Hermite interpolation on admissible hyperplane configurations. Building on this, it presents a comprehensive univariate framework for partial fraction decomposition via Lagrange-Newton and Lagrange-Taylor formulas, providing explicit coefficients for general, multiple-root, and real rational functions. The results yield concrete, implementable formulas for real partial fraction decompositions, leveraging derivatives of reduced rational functions and organized pole structures. Overall, the work bridges multivariate interpolation with classical univariate decomposition, offering direct computational tools for both Hermite interpolation in several variables and rational function decomposition.
Abstract
We present a new formula for the Hermite multivariate interpolation corresponding to the Chung-Yao interpolation. With the help of the respective univariate interpolation formula we give a direct and explicit solution to the problem of partial fraction decomposition of rational functions.
