1. Counting sums of exceptional units in Zn.
- Author
-
Junyong Zhao
- Subjects
CONGRUENCES & residues ,CIRCULANT matrices ,MATHEMATICS ,INTEGERS ,NITROGEN - Abstract
Let R be a commutative ring with the identity 1R, and let R
* be the multiplicative group of units in R. An element a ∈ R* is called an exceptional unit if there exists a b ∈ R* such that a + b = 1R . We set R** to be the set of all exceptional units in R. In this paper, we consider the residue-class ring Zn . For any positive integers n, s, and c ∈ Zn , let Ns(n, c) :=#{(x1 , ..., xs ) ∈ (Z** n )s : x1 + ... + xs (n, c). Later on, Yang and Zhao (Monatsh. Math. 182 (2017)) extended Sander’s theorem to finite terms by using exponential sum theory. In this paper, using matrix theory, we present an explicit formula for N2 (n, c). Later on, Yang and Zhao (Monatsh. Math. 182 (2017)) extended Sander’s theorem to finite terms by using exponential sum theory. In this paper, using matrix theory, we present an explicit formula for Ns (n, c). This extends and improves earlier results. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF