# Simplicity of Ore monoid rings

## TL;DR

This paper introduces Ore monoid rings, generalizing classical Ore extensions and differential polynomial rings, and provides conditions for their simplicity, offering new proofs and examples of these algebraic structures.

## Contribution

It defines Ore monoid rings and differential monoid rings, generalizing existing structures, and characterizes simplicity conditions for commutative monoids, with applications to classical results.

## Key findings

- Necessary and sufficient conditions for simplicity of differential monoid rings.
- New proofs of classical simplicity results for differential polynomial rings.
- Examples of new Ore-like structures from finite commutative monoids.

## Abstract

Given a non-associative unital ring $R$, a monoid $G$ and a set $\pi$ of additive maps $R \rightarrow R$, we introduce the Ore monoid ring $R[\pi ; G]$, and, in a special case, the differential monoid ring. We show that these structures generalize, in a natural way, not only the classical Ore extensions and differential polynomial rings, but also the constructions, introduced by Cojuhari, defined by so-called $D$-structures $\pi$. Moreover, for commutative monoids, we give necessary and sufficient conditions for differential monoid rings to be simple. We use this in a special case to obtain new and shorter proofs of classical simplicity results for differential polynomial rings in several variables previously obtained by Voskoglou and Malm by other means. We also give examples of new Ore-like structures defined by finite commutative monoids.