92.
Let
R be a commutative ring with 1 ≠ 0,
G be a nontrivial finite group, and let
Z(
R) be the set of zero divisors of
R. The zero-divisor graph of
R is defined as the graph Γ(
R) whose vertex set is
Z(
R)* =
Z(
R)?{0} and two distinct vertices
a and
b are adjacent if and only if
ab = 0. In this paper, we investigate the interplay between the ring-theoretic properties of group rings
RG and the graph-theoretic properties of Γ(
RG). We characterize finite commutative group rings
RG for which either diam(Γ(
RG)) ≤2 or gr(Γ(
RG)) ≥4. Also, we investigate the isomorphism problem for zero-divisor graphs of group rings. First, we show that the rank and the cardinality of a finite abelian p-group are determined by the zero-divisor graph of its modular group ring. With the notion of zero-divisor graphs extended to noncommutative rings, it is also shown that two finite semisimple group rings are isomorphic if and only if their zero-divisor graphs are isomorphic. Finally, we show that finite noncommutative reversible group rings are determined by their zero-divisor graphs.
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