Compressed zero-divisor graphs of noncommutative rings

TL;DR

This paper generalizes the compressed zero-divisor graph concept to noncommutative rings, analyzing its properties for matrix rings over finite fields and establishing graph-theoretic characterizations of ring automorphisms.

Contribution

It introduces a functorial extension of the zero-divisor graph to noncommutative rings and characterizes automorphisms for matrix rings, linking graph isomorphisms to ring isomorphisms.

Findings

Graph automorphisms of $ heta(M_n(F))$ are induced by ring automorphisms for $n eq 2,3$

Isomorphism of zero-divisor graphs implies ring isomorphism for certain finite rings

Provides a graph-theoretic characterization of matrix rings over finite fields

Abstract

We extend the notion of the compressed zero-divisor graph $\varTheta(R)$ to noncommutative rings in a way that still induces a product preserving functor $\varTheta$ from the category of finite unital rings to the category of directed graphs. For a finite field $F$, we investigate the properties of $\varTheta(M_n(F))$, the graph of the matrix ring over $F$, and give a purely graph-theoretic characterization of this graph when $n \neq 3$. For $n \neq 2$ we prove that every graph automorphism of $\varTheta(M_n(F))$ is induced by a ring automorphism of $M_n(F)$. We also show that for finite unital rings $R$ and $S$, where $S$ is semisimple and has no homomorphic image isomorphic to a field, if $\varTheta(R) \cong \varTheta(S)$, then $R \cong S$. In particular, this holds if $S=M_n(F)$ with $n \neq 1$.