Turkish Journal of Mathematics
Author ORCID Identifier
CÉSAR A. HERNANDEZ MELO: 0009-0003-7194-4543
FERNANDA DINIZ de MELO HERNANDEZ: 0009-0002-9545-9852
PATRICIA MASSAE KITANI: 0000-0003-1557-6486
Abstract
Let R be an associative ring with identity, Cn be the cyclic group of order n, and g be a generator of Cn. In this manuscript, for i ∈ N such that 1 ≤ i < n and gcd(i, n) = 1, the algebraic properties of the trinomial elements hi = -1 + g + g-i in the group ring RCn are investigated. More precisely, necessary and sufficient conditions are given for an element hi to be a unit in RCn. When hi is a unit, explicit formulas for computing its inverse are provided. In addition, appropriate upper bounds for the orders of the elements hi in group rings Rq Cp are given when p is a prime number and Rq is a ring of prime characteristic q. Those results are extended to rings RCp where p is a prime number and R satisfies some mild conditions. When p = 5 and p = 7, recurrence formulas for the coefficients of the powers of hi in the ring RCp are established. Moreover, upper bounds for orders of symmetric units with augmentation 1 in group rings Rq Cp are established when Rq satisfies some additional conditions.
DOI
10.55730/1300-0098.3622
Keywords
Group rings, trinomial units, orders
First Page
738
Last Page
754
Publisher
The Scientific and Technological Research Council of Türkiye (TÜBİTAK)
Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.
Recommended Citation
HERNANDEZ MELO, C, DINIZ de MELO HERNANDEZ, F, & MASSAE KITANI, P (2025). On trinomial units of the group ring RCn. Turkish Journal of Mathematics 49 (6): 738-754. https://doi.org/10.55730/1300-0098.3622