Definition:Center (Abstract Algebra)/Ring

From ProofWiki
Jump to navigation Jump to search

This page is about the center of a ring. For other uses, see Definition:Center.


The center of a ring $\struct {R, +, \circ}$, denoted $\map Z R$, is the subset of elements in $R$ that commute with every element in $R$.


$\map Z R = \map {C_R} R = \set {x \in R: \forall s \in R: s \circ x = x \circ s}$

That is, the center of $R$ is the centralizer of $R$ in $R$ itself.

It is clear that the center of a ring $\struct {R, +, \circ}$ can be defined as the center of the group $\struct {R, \circ}$.

Linguistic Note

The British English spelling of center is centre.

The convention on $\mathsf{Pr} \infty \mathsf{fWiki}$ is to use the American English spelling center, but it is appreciated that there may be lapses.