- Constructive Mathematical Analysis
- Vol: 5 Issue: 2
- Approximating sums by integrals only: multiple sums and sums over lattice polytopes
Approximating sums by integrals only: multiple sums and sums over lattice polytopes
Authors : Iosif Pinelis
Pages : 72-92
Doi:10.33205/cma.1102689
View : 13 | Download : 8
Publication Date : 2022-06-15
Article Type : Research
Abstract :The Euler--Maclaurin (EM) summation formula is used in many theoretical studies and numerical calculations. It approximates the sum $\sum_{k=0}^{n-1} f(k)$ of values of a function $f$ by a linear combination of a corresponding integral of $f$ and values of its higher-order derivatives $f^{(j)}$. An alternative (Alt) summation formula was presented by the author, which approximates the sum by a linear combination of integrals only, without using derivatives of $f$. It was shown that the Alt formula will in most cases outperform the EM formula. In the present paper, a multiple-sum/multi-index-sum extension of the Alt formula is given, with applications to summing possibly divergent multi-index series and to sums over the integral points of integral lattice polytopes.Keywords : Euler-Maclaurin summation formula, alternative summation formula, multiple sums, multi-index series, approximation, lattice polytopes