Centre of a ring

In ring theory, the centre of a ring is the set of elements which commute with every element of the ring:

$Z(R)=\{x\in R:\forall r\in R,xr=rx\}.\,$

The centre is a subring.

References

• Serge Lang (1993). Algebra, 3rd ed. Addison-Wesley, 84. ISBN 0-201-55540-9.