Steinberg group (K-theory)

In algebraic K-theory, a field of mathematics, the Steinberg group ${\displaystyle \operatorname {St} (A)}$ of a ring ${\displaystyle A}$ is the universal central extension of the commutator subgroup of the stable general linear group of ${\displaystyle A}$.

It is named after Robert Steinberg, and it is connected with lower ${\displaystyle K}$-groups, notably ${\displaystyle K_{2}}$ and ${\displaystyle K_{3}}$.

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